{"title":"Grade 3 Math: Number \u0026 Operations in Base Ten","description":"\u003cp\u003e3rd grade math worksheets and activities for number \u0026amp; operations in base ten (Common Core 3.NBT): printable mystery worksheets, CSI cases and digital escape rooms.\u003c\/p\u003e","products":[{"product_id":"3-digit-addition-regrouping-mystery-detective-worksheets","title":"3-Digit Addition with Regrouping | Mystery Detective Worksheets | Grades 2–5 | Printable Detective Pack","description":"\u003cp\u003e3 digit addition with regrouping math activities for 2nd grade and 3rd grade: five math cases, each a Mystery Detective page of column sums. Print and go with full answer keys: no prep math worksheets for morning work, math centers, early finishers, homework and sub plans. Three digit addition with regrouping practice for 2nd grade and 3rd grade, set around school so it fits any week of the year. It runs as a math center, a homework set or a 3rd grade math review, and the CSI Mini Mystery Detective format means students check their own work.\u003c\/p\u003e\n\n\u003cp\u003eThree digit carrying is where a class learns to write the columns out properly, and five cases with a missing hat make that the fun part. Every page is self-marking, and five math pages make one Mystery Detective download.\u003c\/p\u003e\n\u003cp\u003eStudents carry across the tens and hundreds to find each total, then use it to cross off one clue. Each page has four clue lists: who, where, when and what. The stories are about school life, like missing pens and a lost school hat. When students finish with one clue left in every list, they know their carrying was right.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe Missing Pens\u003c\/strong\u003e - pens gone from the classroom\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe Mystery Gift\u003c\/strong\u003e - a present with no name on it\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe Vacation\u003c\/strong\u003e - a student's surprise trip\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe Missing Hat\u003c\/strong\u003e - a lost school hat\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eStudent Prize\u003c\/strong\u003e - good deeds and a prize\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFive color case pages of 3 digit addition with regrouping\u003c\/li\u003e\n  \u003cli\u003eThe same five in black and white\u003c\/li\u003e\n  \u003cli\u003eAn answer key for each case\u003c\/li\u003e\n  \u003cli\u003eFour clue lists on every page\u003c\/li\u003e\n  \u003cli\u003eTeacher instructions\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eIt's a printed case on a single page: a crime at the top, addition problems underneath and short clue lists beside them. Every clue has a number. Students cross off clues as their answers match, and the leftovers are the solution.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eUse it once 3 digit addition has been taught and students are ready to practice on their own. It's also good to have after a long break, when carrying needs a refresher. The cases suit math centers, small groups, sub days and homeschool.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eWritten for 2nd grade and 3rd grade. 3rd graders can use it before 4 digit addition starts.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003ePrint and hand out\u003c\/li\u003e\n  \u003cli\u003eColor and black and white\u003c\/li\u003e\n  \u003cli\u003eSchool stories\u003c\/li\u003e\n  \u003cli\u003eStudents can check their own totals\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWant more cases like these?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52010352607602,"sku":"4923114","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/3-digit-addition-with-regrouping-worksheets-2nd-3rd-grade-4923114.jpg?v=1792462233"},{"product_id":"3-digit-subtraction-regrouping-mystery-detective-worksheets","title":"3-Digit Subtraction with Regrouping | Mystery Detective Worksheets | Grades 2–5 | Printable Detective Pack","description":"\u003cp\u003e3 digit subtraction with regrouping worksheets for 2nd grade and 3rd grade, five Mystery Detective math cases with borrowing across the columns throughout. No prep math activities, print and go with full answer keys, for morning work, math centers, early finishers, homework and sub plans. School stories carry the cases, so this 3 digit subtraction with regrouping practice suits 2nd grade and 3rd grade in any month. Teachers use it as a math center, a homework set or subtraction review, and one CSI Mini Mystery Detective download covers the week.\u003c\/p\u003e\n\n\u003cp\u003eBorrowing across two columns is the part of the subtraction unit that needs the most practice, and five short cases with a prize and no winner get it practiced with real enthusiasm. Each answer knocks one clue off the list, so every page is self-marking. One CSI Mini Mystery Detective math case a day covers the week.\u003c\/p\u003e\n\u003cp\u003eEvery problem needs borrowing, and some need it across two columns. Students solve each one, then cross off the clue with the same number. The cases are set around school, with a lost library book, money found on the ground and a class prize. Students can check their own borrowing as they work.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe Missing Book\u003c\/strong\u003e - a library book that hasn't come back\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMoney Found\u003c\/strong\u003e - whose money is on the ground\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCaught Being Good\u003c\/strong\u003e - a student doing good deeds\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe Missing Ball\u003c\/strong\u003e - finding the owner of a ball\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe Class Prize\u003c\/strong\u003e - who wins, and what for\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFive color case pages of 3 digit subtraction with regrouping\u003c\/li\u003e\n  \u003cli\u003eThe same cases in black and white\u003c\/li\u003e\n  \u003cli\u003eAn answer key for each case\u003c\/li\u003e\n  \u003cli\u003eProblems set out in columns\u003c\/li\u003e\n  \u003cli\u003eTeacher instructions\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eIt's one page with a short crime story, a set of subtraction problems and clue lists for who, where and when. Each clue carries a number. Matching answers cross clues off, and the ones left over solve the case.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eUse this pack once borrowing has been taught and your class needs practice on their own. It works again as review before a test, or for 3rd graders who need a refresher before 4 digit subtraction. You can hand out one case at a time. They're handy as homework, for early finishers and in homeschool.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eWritten for 2nd grade and 3rd grade. 2nd graders meet borrowing here, and 3rd graders use it for review.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003ePrint and go\u003c\/li\u003e\n  \u003cli\u003eBoth color and black and white\u003c\/li\u003e\n  \u003cli\u003eStudents see right away if an answer doesn't match\u003c\/li\u003e\n  \u003cli\u003eSchool stories kids know\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWant more cases like these?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52011195531634,"sku":"4932127","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/3-digit-subtraction-with-regrouping-worksheets-2nd-3rd-grade-4932127.jpg?v=1792462370"},{"product_id":"addition-subtraction-summer-csi-mystery","title":"Summer Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 2–5 | The Missing Hot Dogs","description":"\u003cp\u003eAre you looking for addition and subtraction math activities wrapped inside a CSI Mystery Detective? Then these \u003cstrong\u003eaddition with regrouping worksheets and mixed word problems\u003c\/strong\u003e are for you. Although this has a summer theme, it is also perfect for \u003cstrong\u003eend-of-year math review\u003c\/strong\u003e, \u003cstrong\u003eseasonal spiral practice\u003c\/strong\u003e, and \u003cstrong\u003eback-to-school math centers\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003eCapture your students' attention with this CSI Mystery Detective by taking them on a journey to solve addition and subtraction problems and puzzles. Students narrow down the possible options by completing the activities and worksheets and marking them off until one person is left. Can you find that person?\u003c\/p\u003e\n\n\u003cp\u003eThis detective case includes:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eSubtraction from 100 of 2-digit numbers\u003c\/li\u003e\n  \u003cli\u003e3-digit addition with regrouping\u003c\/li\u003e\n  \u003cli\u003eAddition and subtraction with 3 digits\u003c\/li\u003e\n  \u003cli\u003eMulti-digit addition\u003c\/li\u003e\n  \u003cli\u003eWord problems with addition and subtraction\u003c\/li\u003e\n  \u003cli\u003eIncludes color and black and white versions\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThese Mystery Detectives are designed for 2nd, 3rd, and 4th grade students. They can also be used with struggling 5th grade students who need a little extra work and reinforcement in adding and takeaways—or to challenge gifted and talented 2nd graders. These printable math puzzles are also great to leave for a sub or to use for \u003cstrong\u003eno-prep math review days\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCSI Mystery Detective packs are an independent escape room or crack the code type of fun math activity where instead of using locks, students identify suspects with puzzles and word problems.\u003c\/strong\u003e This mystery is perfect for the start of the year with \u003cstrong\u003eback-to-school problem solving activities\u003c\/strong\u003e and printable math detective fun.\u003c\/p\u003e\n\n\u003cp\u003eLove this resource? Follow \u003cstrong\u003eKiwiland Education\u003c\/strong\u003e to discover more CSI Mystery Detective packs and receive updates, discounts, and exciting new printables for your classroom.\u003c\/p\u003e\n\n\u003cp\u003eThank you\u003c\/p\u003e\n\n\u003cp\u003eKiwiland\u003c\/p\u003e\n\n\u003cp\u003eIf you are interested in this product and your students enjoy mysteries, I have additional resources that will complement this one.\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery Detective - Alien Invasion\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery Detective - Zombie Attack\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery Detective - Jungle Juice Fever\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52106387587442,"sku":"9566799","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/addition-and-subtraction-1-9566799.jpg?v=1792460141"},{"product_id":"addition-subtraction-csi-mystery-ai-classroom-takeover","title":"Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 3–5 | AI Classroom Takeover","description":"\u003cp\u003eLooking for a fun and low-prep way to review addition and subtraction with regrouping? 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It's a great way to reinforce fluency and critical thinking in a meaningful context.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Included:\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eAdding multiple 2-digit numbers\u003c\/li\u003e\n  \u003cli\u003e3-digit addition with regrouping\u003c\/li\u003e\n  \u003cli\u003eSubtraction from 1000\u003c\/li\u003e\n  \u003cli\u003e3-digit subtraction with regrouping\u003c\/li\u003e\n  \u003cli\u003eAnswer sheets included\u003c\/li\u003e\n  \u003cli\u003ePrint-and-go format (color and black-and-white)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eCSI Mystery Detective packs are independent escape room or crack-the-code types of fun math activities where instead of using locks, students identify suspects using puzzles and word problems. They're perfect for back-to-school, summer school, or end-of-year math review.\u003c\/p\u003e\n\n\u003cp\u003eThis mystery is designed for 3rd and 4th grade students, but can also be used with struggling 5th graders who need extra practice or gifted 2nd grade students looking for a challenge. These make excellent sub plans or review tasks for early finishers—and are also a hit with homeschool families!\u003c\/p\u003e\n\n\u003cp\u003eLove this resource? Follow Kiwiland Education to discover more addition and subtraction Mystery Detectives, printable CSI games, and engaging seasonal activities!\u003c\/p\u003e\n\n\u003cp\u003eClick to follow me\u003c\/p\u003e\n\n\u003cp\u003eThank you\u003c\/p\u003e\n\n\u003cp\u003eKiwiland Education\u003c\/p\u003e\n\n\u003cp\u003eIf you are interested in this product and your students enjoy Mystery Detectives, I have additional resources that will complement this one.\u003c\/p\u003e\n\n\u003cp\u003eCSI: CSI Mystery Detective - Alien Invasion\u003c\/p\u003e\n\n\u003cp\u003eCSI: CSI Mystery Detective - Zombie Attack\u003c\/p\u003e\n\n\u003cp\u003eCSI: CSI Mystery Detective - Jungle Juice Fever\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52173970735474,"sku":"11976567","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/3-digit-addition-and-subtraction-worksheets-regrouping-mystery-detective-printable-11976567.jpg?v=1792459386"},{"product_id":"summer-school-csi-mystery-addition-subtraction-worksheets","title":"Summer School Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 3–6 | The Missing Teacher","description":"\u003cp\u003eLooking for a fun \u003cstrong\u003esummer school math activity\u003c\/strong\u003e to review \u003cstrong\u003eaddition and subtraction with regrouping\u003c\/strong\u003e? This printable \u003cstrong\u003eCSI Mystery Detective\u003c\/strong\u003e is a no-prep set of CSI math worksheets, perfect for \u003cstrong\u003e3rd grade and 4th grade\u003c\/strong\u003e students and also useful for \u003cstrong\u003estruggling 5th graders\u003c\/strong\u003e who need reinforcement with adding and subtracting. It's a great fit for \u003cstrong\u003eend of year math\u003c\/strong\u003e, \u003cstrong\u003esummer review\u003c\/strong\u003e, or \u003cstrong\u003elow-prep math centers\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003eIn this engaging detective-style game, students solve a series of puzzles and eliminate suspects as they work through the challenges. They'll be eager to uncover the culprit while reviewing key computation skills in a meaningful, fun way.\u003c\/p\u003e\n\n\u003cp\u003eThis no-prep case is perfect for \u003cstrong\u003eclassroom use\u003c\/strong\u003e, \u003cstrong\u003esummer school\u003c\/strong\u003e, \u003cstrong\u003ehomework\u003c\/strong\u003e, \u003cstrong\u003eearly finishers\u003c\/strong\u003e, and \u003cstrong\u003ehomeschool enrichment\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Included:\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eAdding multiple 2-digit numbers\u003c\/li\u003e\n  \u003cli\u003e3-digit addition with regrouping\u003c\/li\u003e\n  \u003cli\u003eSubtraction from 1000\u003c\/li\u003e\n  \u003cli\u003e3-digit subtraction with regrouping\u003c\/li\u003e\n  \u003cli\u003ePrintable in color and black-and-white\u003c\/li\u003e\n  \u003cli\u003eAnswer key included\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eCSI Mystery Detective packs are independent escape room or crack-the-code types of fun activities where students identify suspects using puzzles and word problems instead of locks.\u003c\/strong\u003e This summer-themed case makes review exciting while building accuracy and confidence.\u003c\/p\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow \u003cstrong\u003eKiwiland Education\u003c\/strong\u003e to discover more \u003cstrong\u003eaddition and subtraction worksheets\u003c\/strong\u003e, \u003cstrong\u003esummer math activities\u003c\/strong\u003e, and CSI-style printable cases for your classroom.\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52240555606386,"sku":"9653294","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/summer-school-addition-subtraction-mystery-detective-grades-3-5-9653294.jpg?v=1792460143"},{"product_id":"halloween-mystery-detective-3-digit-addition-subtraction","title":"3-Digit Addition \u0026 Subtraction | Mystery Detective Worksheets | Grades 2–5 | Halloween","description":"\u003cp\u003eHalloween 3 digit addition and subtraction worksheets for 2nd grade and 3rd grade: five Halloween math cases, each a Mystery Detective page with carrying and borrowing across the columns. 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The page mixes both operations, so they have to watch the sign.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTeacher Toad\u003c\/strong\u003e - the teacher turned into a toad\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTrick or Treat Teacher\u003c\/strong\u003e - who surprised the teacher\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCat Friend\u003c\/strong\u003e - a friend turned into a cat\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUnder the Costume\u003c\/strong\u003e - who is in the costume\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCostume Competition\u003c\/strong\u003e - who won the competition\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFive Halloween cases\u003c\/li\u003e\n  \u003cli\u003e3 digit addition and subtraction with regrouping\u003c\/li\u003e\n  \u003cli\u003eBlack and white copies\u003c\/li\u003e\n  \u003cli\u003eAnswer keys\u003c\/li\u003e\n  \u003cli\u003eTeacher instructions\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eEach case is one page with a Halloween story, the problems and clue lists. Clues have numbers. Students cross off the ones that match, and what's left solves the case.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eUse these in October, around Halloween. They also work as mixed addition and subtraction review later in the year. Teachers use them as homework, with small groups, on sub days and at class parties.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eWritten for 2nd grade and 3rd grade. 3rd graders can use it as October review.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eHalloween stories kids will like\u003c\/li\u003e\n  \u003cli\u003eAddition and subtraction together\u003c\/li\u003e\n  \u003cli\u003ePrint and go\u003c\/li\u003e\n  \u003cli\u003eFive separate cases\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWant more cases like these?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52291164995954,"sku":"4938843","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/halloween-3-digit-addition-and-subtraction-worksheets-2nd-3rd-grade-4938843.jpg?v=1792462234"},{"product_id":"zoo-mystery-detective-3-digit-subtraction-worksheets","title":"3-Digit Subtraction with Regrouping | Mystery Detective Worksheets | Grades 2–5 | Zoo Animal Theme","description":"\u003cp\u003e3 digit subtraction with regrouping zoo safari math worksheets for 2nd grade and 3rd grade: five zoo math cases, each a Mystery Detective page. Print and go with full answer keys: no prep math activities for math centers, morning work, early finishers, homework and sub plans. The zoo setting makes this the obvious 3 digit subtraction with regrouping practice for an animal unit or a zoo trip, for 2nd grade and 3rd grade. Teachers use it as zoo math for math centers, morning work or homework, and every CSI Mini Mystery Detective page is self-marking.\u003c\/p\u003e\n\n\u003cp\u003eA class that has just been to the zoo, or is about to go, will do subtraction with real enthusiasm, and an animal loose from its pen is why they race to the last sum. Every answer rules out a suspect, so the pages mark themselves. Pair it with the zoo addition pack for a full CSI Mini Mystery Detective math week.\u003c\/p\u003e\n\u003cp\u003eThe cases happen on a class trip to the zoo, where an animal is hiding, a classmate goes missing and someone walks off with a bag. Students borrow across the columns to find each answer, then cross off the matching animal, place or time. It fits nicely alongside an animal unit.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSpot the Animal\u003c\/strong\u003e - which animal is in the enclosure\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDisappearing Classmate\u003c\/strong\u003e - a classmate lost at the zoo\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMissing Bag\u003c\/strong\u003e - who took the bag\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAnimal Noise\u003c\/strong\u003e - which animal made the sound\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMissing Animal\u003c\/strong\u003e - an animal gone from its enclosure\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFive zoo cases of 3 digit subtraction with regrouping\u003c\/li\u003e\n  \u003cli\u003eProblems set out in columns\u003c\/li\u003e\n  \u003cli\u003eBlack and white copies\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for every case\u003c\/li\u003e\n  \u003cli\u003eTeacher instructions\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eEach case fits on one page, with the story at the top and the clue lists down the side. Every clue carries a number. Students cross off the ones their answers match, and the clue left in each list solves the case.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eBring these out after borrowing across columns has been taught, or the week of a zoo field trip. 3rd graders can use them as fluency practice. Small groups, early finishers, sub days and homeschool lessons all work too.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eWritten for 2nd grade and 3rd grade, and handy inside an animal unit.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eA zoo trip in every case\u003c\/li\u003e\n  \u003cli\u003eNo prep\u003c\/li\u003e\n  \u003cli\u003eStudents check their own borrowing\u003c\/li\u003e\n  \u003cli\u003eFive separate cases\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWant more cases like these?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52291328344434,"sku":"4947535","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/3-digit-subtraction-with-regrouping-worksheets-2nd-3rd-grade-zoo-theme-4947535.jpg?v=1792462370"},{"product_id":"zoo-mystery-detective-3-digit-addition-worksheets","title":"3-Digit Addition with Regrouping | Mystery Detective Worksheets | Grades 2–5 | Zoo Animal Theme","description":"\u003cp\u003eZoo animals 3 digit addition with regrouping math worksheets, five Mystery Detective cases for 2nd grade and 3rd grade in one download. Print and go, full answer keys, no prep, for math centers, morning work, early finishers, homework and sub plans. Zoo math for 2nd grade and 3rd grade, with 3 digit addition with regrouping on every page and a day at the zoo running through the cases. It pairs with an animal unit, a zoo trip or a plain need for regrouping practice, and the CSI Mini Mystery Detective format means students check their own work.\u003c\/p\u003e\n\n\u003cp\u003eAn animal unit, a zoo trip or the week either side of one is where this set earns its place, because the cases are all at the zoo and the addition underneath is the real work. Students add, match the total to a clue and cross it off, and the marking is student-led from the first page. Five math pages fill one Mystery Detective download, answer keys included.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSpot the Animal\u003c\/strong\u003e - something is hiding in the enclosure\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDisappearing Classmate\u003c\/strong\u003e - a classmate lost at the zoo\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMissing Bag\u003c\/strong\u003e - somebody has walked off with a bag\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAnimal Noise\u003c\/strong\u003e - a sound, and nobody can name it\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMissing Animal\u003c\/strong\u003e - one animal is out of its pen\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eFive zoo cases, each a page of 3 digit addition with regrouping\u003c\/li\u003e\n  \u003cli\u003eSixteen sums per case, set out in columns ready to carry\u003c\/li\u003e\n  \u003cli\u003eClue lists down the side of each page, so one answer removes one clue\u003c\/li\u003e\n  \u003cli\u003eA black and white copy of all five cases for everyday printing\u003c\/li\u003e\n  \u003cli\u003eAn answer key for every case\u003c\/li\u003e\n  \u003cli\u003ePrint and go: no cutting, no laminating, nothing to prepare\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mini Mystery Detective is one printed page with a crime on it and the clues that solve it listed beside the questions. Each clue has a number, the sums produce those numbers, and a correct answer crosses that clue off. When the last question is finished the untouched clues are the answer. It works like an escape room with no locks, no app and nothing to charge overnight.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThis is the pack for a zoo or animal habitats unit, and for the week before or after a trip when the class is still full of it and you want the addition practice to ride along with the theme. It also works any other week of the year, because the math is a standard three digit carrying set and the zoo is only the setting. The instructions are on the page, so a relief teacher needs nothing explained.\u003c\/p\u003e\n\n\u003cp\u003eUse it for math centers, morning work, early finishers, homework, sub plans and homeschool lessons, with a whole class, a small group or one student.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWritten for 2nd grade and 3rd grade. Second graders use these once carrying across columns is understood, and third graders use them as a fluency set alongside an animal unit.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eThe zoo setting sells it to a class that has gone off worksheets\u003c\/li\u003e\n  \u003cli\u003eNothing to prepare, print and hand out\u003c\/li\u003e\n  \u003cli\u003eFive separate cases means five days without a repeated page\u003c\/li\u003e\n  \u003cli\u003eSuits a whole class, a small group, partners or one student\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52291330867570,"sku":"4947315","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/3-digit-addition-with-regrouping-worksheets-2nd-3rd-grade-zoo-theme-4947315.jpg?v=1792460694"},{"product_id":"addition-subtraction-csi-mystery-grades-3-5-missing-dragon-eggs","title":"Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 3–6 | The Missing Dragon Eggs","description":"\u003cp\u003eAre you looking for an exciting \u003cstrong\u003efantasy-themed addition and subtraction activity\u003c\/strong\u003e to engage your 3rd, 4th, or 5th grade students? \u003cstrong\u003eThe Missing Dragon Eggs\u003c\/strong\u003e is a \u003cstrong\u003eCSI Mystery Detective\u003c\/strong\u003e pack of CSI math worksheets that combines regrouping practice with a magical detective twist—perfect for building number sense, critical thinking, and problem-solving.\u003c\/p\u003e\n\n\u003cp\u003eIn this independent \u003cstrong\u003ecrack-the-code style\u003c\/strong\u003e case, students become detectives solving puzzles to eliminate suspects and find out who stole the dragon eggs. With minimal prep required, this printable activity is ideal for back to school, end of year review, or anytime you want to boost engagement in your classroom or homeschool.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThis case includes:\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eAdding multiple 2-digit numbers together\u003c\/li\u003e\n  \u003cli\u003eAddition of 3-digit numbers\u003c\/li\u003e\n  \u003cli\u003eSubtraction from 1000\u003c\/li\u003e\n  \u003cli\u003e3-digit addition with regrouping\u003c\/li\u003e\n  \u003cli\u003e3-digit subtraction from 1000\u003c\/li\u003e\n  \u003cli\u003eIncludes both color and black-and-white versions\u003c\/li\u003e\n  \u003cli\u003eAnswer sheets included\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThis fun activity is designed for \u003cstrong\u003e3rd and 4th grade\u003c\/strong\u003e, but is also great for \u003cstrong\u003estruggling 5th graders\u003c\/strong\u003e who need review or \u003cstrong\u003eadvanced 2nd graders\u003c\/strong\u003e ready for a challenge. It also works well in homeschool settings, for review, and as an engaging activity for substitute days.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCSI Mystery Detective packs\u003c\/strong\u003e are a unique, low-prep alternative to escape rooms that use puzzles instead of locks. Students must crack the code to solve the case and identify the culprit—keeping them motivated and learning.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eLove this resource?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education to discover more engaging CSI Mystery Detective cases and receive updates, discounts, and exciting new printables for your classroom.\u003c\/p\u003e\n\n\u003cp\u003eThank you\u003c\/p\u003e\n\n\u003cp\u003eKiwiland\u003c\/p\u003e\n\n\u003cp\u003eIf you are interested in this product and your students enjoy mysteries, I have additional resources that will complement this one.\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery - Alien Invasion: \u003ca href=\"https:\/\/www.teacherspayteachers.com\/Product\/CSI-Mystery-Alien-Invasion-3789957\"\u003ehttps:\/\/www.teacherspayteachers.com\/Product\/CSI-Mystery-Alien-Invasion-3789957\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery - Zombie Attack: \u003ca href=\"https:\/\/www.teacherspayteachers.com\/Product\/CSI-Mystery-Zombie-Attack-3799849\"\u003ehttps:\/\/www.teacherspayteachers.com\/Product\/CSI-Mystery-Zombie-Attack-3799849\u003c\/a\u003e\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery - Jungle Juice Fever: \u003ca href=\"https:\/\/www.teacherspayteachers.com\/Product\/CSI-Mystery-Jungle-Juice-Fever-3765647\"\u003ehttps:\/\/www.teacherspayteachers.com\/Product\/CSI-Mystery-Jungle-Juice-Fever-3765647\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52309264695666,"sku":"9597857","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/the-missing-dragon-eggs-addition-subtraction-mystery-detective-grades-3-5-9597857.jpg?v=1792459386"},{"product_id":"spring-csi-mystery-addition-subtraction-worksheets","title":"Spring Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 2–5 | The Missing Flowers","description":"\u003cp\u003eLooking for fun and engaging \u003cstrong\u003espring addition and subtraction worksheets\u003c\/strong\u003e for 3rd and 4th grade? This \u003cstrong\u003eCSI Mystery Detective\u003c\/strong\u003e is the perfect printable \u003cstrong\u003emath activity\u003c\/strong\u003e for Easter, Earth Day, and spring math review after the break. Students will solve puzzles using \u003cstrong\u003e3-digit addition with regrouping\u003c\/strong\u003e, subtraction from 1000, and multi-step problems — all while uncovering clues in a mystery story!\u003c\/p\u003e\n\n\u003cp\u003eThis \u003cstrong\u003eno-prep spring math game\u003c\/strong\u003e will keep students excited and focused as they work through each math puzzle to eliminate suspects. With a detective-style storyline and self-checking clues, this printable resource is ideal for \u003cstrong\u003espiral review, math stations, enrichment, early finishers, or even sub plans\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThis Detective Case Includes:\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eSubtraction from 100 of 2-digit numbers\u003c\/li\u003e\n  \u003cli\u003e3-digit addition with regrouping\u003c\/li\u003e\n  \u003cli\u003eMixed 3-digit addition and subtraction\u003c\/li\u003e\n  \u003cli\u003eMulti-digit addition\u003c\/li\u003e\n  \u003cli\u003eWord problems using addition and subtraction\u003c\/li\u003e\n  \u003cli\u003eColor and black-and-white versions included\u003c\/li\u003e\n  \u003cli\u003eFull answer keys\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThese \u003cstrong\u003espring-themed math worksheets\u003c\/strong\u003e are designed for 3rd and 4th grade students, but they're also great for \u003cstrong\u003estruggling 5th graders\u003c\/strong\u003e who need extra practice with basic operations, or \u003cstrong\u003egifted 2nd graders\u003c\/strong\u003e ready for a challenge. Perfect for \u003cstrong\u003ehomeschoolers\u003c\/strong\u003e, this mystery can be completed independently or in pairs.\u003c\/p\u003e\n\n\u003cp\u003eLove this resource? Follow \u003cstrong\u003eKiwiland Education\u003c\/strong\u003e to discover more \u003cstrong\u003einteractive Mystery Detectives\u003c\/strong\u003e and receive updates, discounts, and exciting new printables for your classroom.\u003c\/p\u003e\n\n\u003cp\u003eThank you\u003c\/p\u003e\n\n\u003cp\u003eKiwiland\u003c\/p\u003e\n\n\u003cp\u003eIf you are interested in this product and your students enjoy mysteries, I have additional resources that will complement this one.\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery Detective - Alien Invasion\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery Detective - Zombie Attack\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery Detective - Jungle Juice Fever\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52309548171634,"sku":"9425399","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/spring-mystery-detective-1-9425399.jpg?v=1792460140"},{"product_id":"earth-day-csi-mystery-addition-subtraction-worksheets","title":"Earth Day Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 2–5 | The Missing Recycling Bins","description":"\u003cp\u003e\u003cstrong\u003eLooking for Earth Day CSI math worksheets that make addition and subtraction fun?\u003c\/strong\u003e This printable CSI Mystery Detective is the perfect spring activity for 2nd, 3rd, and 4th grade students. Designed with Earth Day in mind, these no-prep worksheets are ideal for April math review, Earth Day classroom events, or the days around spring break and Easter.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eIn this engaging CSI-style mystery, students use their math skills to crack the case of the missing seed packets.\u003c\/strong\u003e With every correct answer, they eliminate a suspect and move one step closer to solving the Earth Day-themed mystery. This activity combines addition, subtraction, word problems, and regrouping practice with logic and deduction—no locks or devices needed!\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThis resource is perfect for:\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWhether you need Earth Day math worksheets, spring-themed problem-solving tasks, or fun enrichment for early finishers, this printable CSI Mystery Detective supports classroom instruction, math centers, and even homeschool review. Teachers love using these mysteries as independent work, sub plans, or engaging end-of-week practice. Great for students who need a challenge—and fun for those who enjoy puzzles.\u003c\/p\u003e\n\n\u003cp\u003e✅ What's Included:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eSubtraction from 100 of 2-digit numbers\u003c\/li\u003e\n  \u003cli\u003e3-digit addition with regrouping\u003c\/li\u003e\n  \u003cli\u003e3-digit addition and subtraction\u003c\/li\u003e\n  \u003cli\u003eMulti-digit addition problems\u003c\/li\u003e\n  \u003cli\u003eAddition and subtraction word problems\u003c\/li\u003e\n  \u003cli\u003eColor and black-and-white worksheet versions\u003c\/li\u003e\n  \u003cli\u003eFull answer key\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eCSI Mystery Detective packs are a fun, escape room–style experience\u003c\/strong\u003e where students solve puzzles and eliminate suspects—no locks or devices required. Just print and go! This resource is especially useful for spring classroom review, Earth Day activities, and spiral math practice. Also great for reinforcing skills in a fun, student-led format.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eLove this resource?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eFollow \u003cstrong\u003eKiwiland Education\u003c\/strong\u003e to discover more engaging CSI Mystery Detective packs and receive updates, discounts, and exciting new printables for your classroom.\u003c\/p\u003e\n\n\u003cp\u003eThank you\u003c\/p\u003e\n\n\u003cp\u003eKiwiland\u003c\/p\u003e\n\n\u003cp\u003eIf you are interested in this product and your students enjoy mysteries, I have additional resources that will complement this one.\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery Detective - Alien Invasion\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery Detective - Zombie Attack\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery Detective - Jungle Juice Fever\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52309599158642,"sku":"9369396","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/earth-day-mystery-detective-addition-and-subtraction-1-9369396.jpg?v=1792459542"},{"product_id":"groundhog-day-csi-mystery-addition-subtraction-worksheets","title":"Groundhog Day Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 2–5 | The Missing Groundhog","description":"\u003cp\u003e\u003cstrong\u003eLooking for Groundhog Day math activities to keep your students engaged?\u003c\/strong\u003e This Groundhog Day CSI Mystery Detective combines 3-digit addition and subtraction with an exciting detective twist! Perfect for 2nd, 3rd, and 4th grade students, this fun math review is ideal for January and February, especially in the days leading up to or after Groundhog Day.\u003c\/p\u003e\n\n\u003cp\u003eIn The Missing Groundhog, students become detectives, solving addition and subtraction puzzles to eliminate suspects. With each completed worksheet, they get closer to discovering who took the groundhog. Designed to boost critical thinking and math fluency, this activity turns your math lesson into an engaging adventure.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Included:\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eSubtraction from 100 of 2-digit numbers\u003c\/li\u003e\n  \u003cli\u003e3-digit addition with regrouping\u003c\/li\u003e\n  \u003cli\u003eMixed addition and subtraction (3-digit)\u003c\/li\u003e\n  \u003cli\u003eMulti-digit addition\u003c\/li\u003e\n  \u003cli\u003eWord problems with addition and subtraction\u003c\/li\u003e\n  \u003cli\u003eFull-color and black-and-white versions\u003c\/li\u003e\n  \u003cli\u003eComplete answer sheets for easy grading\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love It:\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThis CSI-style math activity is perfect for back-to-school, Groundhog Day, winter review, or anytime your class needs meaningful math practice. It also works great for early finishers, math centers, sub plans, or holiday-themed lessons. Many teachers report high engagement, especially when using these activities around holidays or seasonally themed events.\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery Detective packs are a fun, escape room–style worksheet activity where students solve clues and eliminate suspects to crack the case—no locks or apps required! If your students love puzzles and detective stories, they'll love these printable math worksheets.\u003c\/p\u003e\n\n\u003cp\u003eLove this resource? Follow Kiwiland Education to discover more CSI Mystery Detective packs and receive updates, discounts, and exciting new printables for your classroom.\u003c\/p\u003e\n\n\u003cp\u003eThank you\u003c\/p\u003e\n\n\u003cp\u003eKiwiland\u003c\/p\u003e\n\n\u003cp\u003eIf you are interested in this product and your students enjoy mysteries, I have additional resources that will complement this one.\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery Detective - Alien Invasion\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery Detective - Zombie Attack\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery Detective - Jungle Juice Fever\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52309751333234,"sku":"9040962","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/groundhog-day-math-1-9040962.jpg?v=1792459696"},{"product_id":"winter-csi-mystery-addition-subtraction-worksheets","title":"Winter Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 2–5 | The Big Freeze","description":"\u003cp\u003e\u003cstrong\u003eAre you looking for a fun and engaging winter math activity to reinforce addition and subtraction?\u003c\/strong\u003e This Frozen Classroom CSI Mystery Detective is perfect for 2nd, 3rd, and 4th grade students who need practice with 3-digit addition and subtraction, including regrouping. Ideal for winter math lessons, post-winter break review, and early finisher tasks, this detective-themed math packet adds excitement to January and February learning!\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eStoryline:\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eGoosebumps appear on your skin as you enter the classroom. Icicles hang from the furniture. Your pencils are frozen together. Who did this? Become a math detective and follow the trail of frosty clues to eliminate suspects and solve the mystery of the frozen classroom!\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Included:\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eSubtraction from 100 of 2-digit numbers\u003c\/li\u003e\n  \u003cli\u003e3-digit addition with regrouping\u003c\/li\u003e\n  \u003cli\u003eAddition and subtraction with 3-digit numbers\u003c\/li\u003e\n  \u003cli\u003eMulti-digit addition\u003c\/li\u003e\n  \u003cli\u003eWord problems with addition and subtraction\u003c\/li\u003e\n  \u003cli\u003eAnswer sheets included\u003c\/li\u003e\n  \u003cli\u003eFull-color and black \u0026amp; white versions for printing flexibility\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThese no-prep printable worksheets are perfect for:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eWinter math centers\u003c\/li\u003e\n  \u003cli\u003eMath review after winter break\u003c\/li\u003e\n  \u003cli\u003eEarly finishers\u003c\/li\u003e\n  \u003cli\u003eSubstitute teacher plans\u003c\/li\u003e\n  \u003cli\u003eEngaging homework or enrichment\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eCSI Mystery Detective packs\u003c\/strong\u003e are a classroom escape-room style activity where students crack the case using math problems instead of locks. Fun, effective, and standards-aligned—your students won't even realize they're practicing key math skills!\u003c\/p\u003e\n\n\u003cp\u003eLove this resource? Follow Kiwiland Education to discover more CSI Mystery Detective packs and receive updates, discounts, and exciting new printables for your classroom.\u003c\/p\u003e\n\n\u003cp\u003eThank you\u003c\/p\u003e\n\n\u003cp\u003eKiwiland\u003c\/p\u003e\n\n\u003cp\u003eIf you are interested in this product and your students enjoy mysteries, I have additional resources that will complement this one.\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery Detective - Alien Invasion\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery Detective - Zombie Attack\u003c\/p\u003e\n\n\u003cp\u003eCSI Mystery Detective - Jungle Juice Fever\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52310638788978,"sku":"8721476","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/winter-mystery-detective-addition-and-subtraction-1-8721476.jpg?v=1792460271"},{"product_id":"halloween-csi-mystery-addition-subtraction-worksheets","title":"Halloween Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 2–5 | The Witch's Brew","description":"\u003cp\u003e\u003cstrong\u003eAre you looking for fun Halloween math activities that actually get your students excited about practicing addition and subtraction?\u003c\/strong\u003e This CSI Mystery Detective is a perfect choice for October math lessons, fall centers, or spooky review days. Designed for 2nd, 3rd, and 4th grade students, this engaging escape room–style math activity builds number fluency, critical thinking, and problem-solving skills—all while students solve a mysterious case of stolen potion ingredients!\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Mystery:\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA witch is in trouble! Her magical ingredients—Dead Sea Salt, Vile Toad Skin, and Snake Skull—have mysteriously vanished under the full moon. She needs your students' math detective skills to uncover who stole them. Can your class crack the case?\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Included:\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eSubtraction from 100 with 2-digit numbers\u003c\/li\u003e\n  \u003cli\u003e3-digit addition with regrouping\u003c\/li\u003e\n  \u003cli\u003e3-digit subtraction from 1000\u003c\/li\u003e\n  \u003cli\u003eMixed 3-digit addition and subtraction\u003c\/li\u003e\n  \u003cli\u003eMulti-digit addition\u003c\/li\u003e\n  \u003cli\u003eWord problems involving addition and subtraction\u003c\/li\u003e\n  \u003cli\u003eColor and black \u0026amp; white versions\u003c\/li\u003e\n  \u003cli\u003eAnswer sheets included\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eSuggested Uses:\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003ePerfect for Halloween math centers, October early finisher tasks, or fun homework. Great for review, sub plans, or even end-of-term challenges. These math worksheets are ideal for independent learning, and work great in homeschool settings too.\u003c\/p\u003e\n\n\u003cp\u003eThis escape-room inspired mystery works without locks! Instead, students eliminate suspects as they solve each puzzle and get closer to finding the culprit. The storyline and puzzles keep them motivated from start to finish.\u003c\/p\u003e\n\n\u003cp\u003eLove this resource? Follow Kiwiland Education to discover more interactive math escape rooms and receive updates, discounts, and exciting new printables for your classroom.\u003c\/p\u003e\n\n\u003cp\u003eThank you\u003c\/p\u003e\n\n\u003cp\u003eKiwiland\u003c\/p\u003e\n\n\u003cp\u003eIf you are interested in this product and your students enjoy mysteries, I have additional resources that will complement this one.\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eCSI Mystery Detective - Alien Invasion\u003c\/li\u003e\n  \u003cli\u003eCSI Mystery Detective - Zombie Attack\u003c\/li\u003e\n  \u003cli\u003eCSI Mystery Detective - Jungle Juice Fever\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52310720282994,"sku":"8595503","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/mystery-detective-halloween-1-8595503.jpg?v=1792459697"},{"product_id":"fall-csi-mystery-addition-subtraction-worksheets","title":"Fall Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 2–5 | Who Stole the Colors?","description":"\u003cp\u003eFall CSI math worksheets, fall addition and subtraction practice, and a Halloween-friendly monster line-up for 2nd grade, 3rd grade and 4th grade - all in one printable Mystery Detective pack. Built for September, October and November: the first cool weeks of fall, the run-up to Halloween, and Thanksgiving week before the break. Completely no prep - just print and go.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case: Who Stole the Colors?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe leaves around school are turning from green to yellow to orange to brown, and then falling off the trees. Someone is stealing the color. Your class takes the case, works the clues, and crosses suspects off the chart until one name is left standing. Every clue answers a different question about the culprit, so the list narrows a little further with each page they finish.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e3-digit addition with regrouping\u003c\/li\u003e\n  \u003cli\u003eAdding 1-digit numbers to 3-digit numbers along a leaf-trail path\u003c\/li\u003e\n  \u003cli\u003eAddition and subtraction word problems, including money and change\u003c\/li\u003e\n  \u003cli\u003eDeciding whether a given equation is right or wrong - error spotting, not just answering\u003c\/li\u003e\n  \u003cli\u003eOdd and even numbers as a way of narrowing the suspects\u003c\/li\u003e\n  \u003cli\u003eReading a suspect chart and matching your answers against it\u003c\/li\u003e\n  \u003cli\u003eAnswer keys included\u003c\/li\u003e\n  \u003cli\u003eColor and black-and-white versions, so it prints clean on any copier\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA Mystery Detective case is a printable escape room with no locks and no boxes. Students solve a page of math, use what the answer tells them to rule suspects out, and keep going until one suspect is left. The pages check themselves - a wrong answer stops the case in its tracks, so students go back and find their own slip before it ever reaches your marking pile.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eFall math centers\u003c\/li\u003e\n  \u003cli\u003eThe lead-up to Halloween, and Halloween week itself\u003c\/li\u003e\n  \u003cli\u003eThanksgiving week and the days before the break\u003c\/li\u003e\n  \u003cli\u003eSeptember, October and November math review\u003c\/li\u003e\n  \u003cli\u003eSub plans and emergency cover\u003c\/li\u003e\n  \u003cli\u003eEarly finishers and morning work\u003c\/li\u003e\n  \u003cli\u003eHomework, small groups and partner work\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eDesigned for 2nd grade, 3rd grade and 4th grade, where 3-digit addition and regrouping sit right on the standards. It also works as review for a 5th grader who still needs practice carrying across columns, and as an extension for a confident 1st grader who is ready to be stretched.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eNo prep at all - print it and hand it out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking, so you are not hunting through thirty pages for one slipped digit\u003c\/li\u003e\n  \u003cli\u003eThe suspect chart gives every student a reason to go back and check their own working\u003c\/li\u003e\n  \u003cli\u003eEvery clue uses a different puzzle shape, so the pack holds attention to the last page\u003c\/li\u003e\n  \u003cli\u003eQuiet, focused engagement in a week when the classroom is anything but\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education to discover more Mystery Detective cases, seasonal math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52310872654194,"sku":"8569960","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/fall-mystery-detective-1-8569960.jpg?v=1792459542"},{"product_id":"summer-csi-mystery-addition-subtraction-worksheets","title":"Summer Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 2–5 | Who Stole Summer?","description":"\u003cp\u003eSummer CSI math worksheets for 3 digit addition and subtraction with regrouping, wrapped in a CSI Mystery Detective case for June and July. The mystery is Who Stole Summer: the vacation, the beach days and the pool afternoons vanished overnight, and your 2nd grade, 3rd grade and 4th grade students have to work out who took them. Subtraction with regrouping from 100, three digit addition with regrouping and addition and subtraction word problems each fill in one more detail about the culprit, until only one suspect fits. Every page comes in color and black-and-white with answer keys, so it is no prep for summer school in July or a June addition and subtraction review.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case: Who Stole Summer?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eSummer is gone. The vacation, the beach days, the long afternoons at the pool with friends - all of it vanished overnight, and nobody at home can explain it. There is only one thing left to do: take the case. Your students work the clues one at a time, and every correct answer fills in another detail about the culprit - what they look like, how old they are, and which season they love most. Get the math right and the description narrows until only one suspect can have done it.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eSubtraction from 100 with two-digit numbers, checked against a right-or-wrong tally\u003c\/li\u003e\n  \u003cli\u003e3-digit addition with regrouping, decoded through a letter key\u003c\/li\u003e\n  \u003cli\u003e3-digit plus single-digit addition solved by matching each problem to its answer\u003c\/li\u003e\n  \u003cli\u003eA running addition trail where the final total decides the answer through odd and even\u003c\/li\u003e\n  \u003cli\u003eAddition and subtraction word problems set in everyday summer situations\u003c\/li\u003e\n  \u003cli\u003eFull color and black-and-white versions of every page\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for the whole case\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eIt is an escape-room-style activity that runs on math instead of padlocks. Each page hands your students a question about the villain and a set of problems that answer it. They solve, they cross suspects off, and the case closes when one name is left standing. The deduction gives the practice a point - students check their own work carefully, because a careless answer sends the whole investigation the wrong way.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eEnd of year review, when attention is thin and the work still has to happen\u003c\/li\u003e\n  \u003cli\u003eSummer school and holiday review packets\u003c\/li\u003e\n  \u003cli\u003eThe first weeks back at school, to see what came back with them\u003c\/li\u003e\n  \u003cli\u003eMath centers, early finishers and independent work\u003c\/li\u003e\n  \u003cli\u003eEmergency sub plans that run themselves\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBuilt for 2nd grade, 3rd grade and 4th grade. Second graders find the 3-digit addition with regrouping a genuine stretch and often work it in pairs; third and fourth graders can usually run the case on their own. It also gives 5th grade students who need addition and subtraction review something that does not look like remedial work.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love CSI Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eZero prep - print and hand out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking by design, because a wrong answer breaks the deduction\u003c\/li\u003e\n  \u003cli\u003eRepeatable practice students ask to do again\u003c\/li\u003e\n  \u003cli\u003eWorks as a whole lesson, a center, or a filler for an awkward afternoon\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education for new detective cases, seasonal math activities and updates on discounts and new releases.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52324094640498,"sku":"8372297","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/summer-addition-and-subtraction-mystery-detective-1-8372297.jpg?v=1792460143"},{"product_id":"summer-addition-subtraction-csi-mystery-worksheets","title":"Summer Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 2–5 | The Missing Skates","description":"\u003cp\u003e3rd grade and 4th grade 3 digit addition CSI math worksheets, dressed as a back to school and summer review CSI Mystery Detective case that earns a second run in March when addition needs tightening before testing. 4 digit addition is in there too, so it doubles as 4th grade math review. Nothing to prepare beyond pressing print: color and black and white versions, answer keys for every page. The case is The Missing Roller Skates - in the bag last night, gone this morning - and your students have until the rink opens to solve the mystery. Answers pick letters off a map and settle an odd-or-even trail, ruling out a suspect each time.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case: The Missing Roller Skates\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eYour best friend has invited you to the rink and you have not been skating in years. You get dressed, find your bag, and the skates are not in it. They were there last night. Somebody has been through the bag between then and now, and the whole afternoon depends on your students working out who it was before the session starts.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e3 digit and 4 digit addition, with answers used to pick letters off a map\u003c\/li\u003e\n  \u003cli\u003eA matching page where the line drawn passes through the letter that matters\u003c\/li\u003e\n  \u003cli\u003eAddition decoded through a letter key to reveal the next part of the description\u003c\/li\u003e\n  \u003cli\u003eAddition along a path where an odd or even final total decides the answer\u003c\/li\u003e\n  \u003cli\u003eA suspect line-up that narrows every time a clue is solved\u003c\/li\u003e\n  \u003cli\u003eFull color and black-and-white versions of every page\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for the whole case\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eEach page asks one question about the thief - the gender, the age, the height, the shoe size - and hands your students the addition that answers it. They solve, they cross a name off the line-up, and the case closes when one suspect is left. A careless answer sends the description the wrong way, so students check their own work properly.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eEnd of year review in June and July, when attention is thin\u003c\/li\u003e\n  \u003cli\u003eSummer school and holiday review packets\u003c\/li\u003e\n  \u003cli\u003eThe first weeks back at school in August and September\u003c\/li\u003e\n  \u003cli\u003eMath centers, early finishers and independent work\u003c\/li\u003e\n  \u003cli\u003eEmergency sub plans that run themselves\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBuilt for 3rd grade and 4th grade. Third graders usually pair up on the four-digit pages; fourth graders run the whole case independently inside a lesson. It also suits 2nd grade students who are ahead on addition and want something with more thinking in it than extra practice.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love CSI Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eZero prep - print and hand out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking by design, because a wrong answer breaks the deduction\u003c\/li\u003e\n  \u003cli\u003eAddition practice students will actually finish\u003c\/li\u003e\n  \u003cli\u003eWorks as a whole lesson, a center, or a filler for an awkward afternoon\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education for new detective cases, seasonal math activities and updates on discounts and new releases.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52324294689138,"sku":"8336949","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/summer-mystery-detective-addition-and-subtraction-1-8336949.jpg?v=1792460144"},{"product_id":"3-digit-addition-subtraction-csi-mystery-haunted-hallway","title":"3-Digit Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 2–5 | The Haunted Hallway","description":"\u003cp\u003eOctober CSI math worksheets with a Halloween case to crack, this CSI Mystery Detective investigation runs on 3 digit addition and subtraction with regrouping from first clue to last. All week things have been going missing from the hallway lockers, and the only useful evidence is a set of numbers. It suits 3rd grade, 4th grade and 5th grade as fun subtraction worksheets or a Halloween math activity, and the routine is print, hand out, done. Students decode sums through a letter key, color the correct arrow, match the locker to its level and add along a path where an odd or even total decides the answer, until the mystery is down to one culprit.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case: The Haunted Hallway\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eAll week teachers have been getting the same report: things are going missing from the lockers in the hallway. Students have been blaming each other, loudly, and nobody has got anywhere near the truth. The lockers are on two levels, there are a lot of them, and the only useful evidence is a set of numbers. Work them out and the right locker - and the right culprit - is the one left standing.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e3 digit subtraction decoded through a letter key\u003c\/li\u003e\n  \u003cli\u003eSubtraction problems used to color the correct arrow to the next clue\u003c\/li\u003e\n  \u003cli\u003eA matching page that identifies which level the locker is on\u003c\/li\u003e\n  \u003cli\u003e3 digit addition decoded through a letter key\u003c\/li\u003e\n  \u003cli\u003eAddition along a path where an odd or even final total decides the answer\u003c\/li\u003e\n  \u003cli\u003eFull color and black-and-white versions of every page\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for the whole case\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eIt plays like a math escape room on paper. Each page asks one question about the locker and the person using it, and hands your students the problems that answer it. They solve, they cross suspects off, and the case closes when one is left - no locks, no props, nothing to reset between classes.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eHalloween week in October, when a normal worksheet will not hold them\u003c\/li\u003e\n  \u003cli\u003e3 digit addition and subtraction review before or after a unit test\u003c\/li\u003e\n  \u003cli\u003eMath centers, early finishers and independent work\u003c\/li\u003e\n  \u003cli\u003eEmergency sub plans that run themselves\u003c\/li\u003e\n  \u003cli\u003eBack-to-school weeks and end of year review\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBuilt for 3rd grade, 4th grade and 5th grade. Third graders usually pair up on the four-digit totals; fourth and fifth graders run the case independently. It also suits 6th grade students who need addition and subtraction review without it feeling like going backwards.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love CSI Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eZero prep - print and hand out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking by design, because a wrong answer breaks the deduction\u003c\/li\u003e\n  \u003cli\u003eA Halloween activity that still does real math\u003c\/li\u003e\n  \u003cli\u003eWorks as a whole lesson, a center, or a filler for an awkward afternoon\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education for new detective cases, seasonal math activities and updates on discounts and new releases.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52334803911026,"sku":"7296432","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/haunted-hallway-halloween-csi-mystery-detective-grades-3-5-7296432.jpg?v=1792459156"},{"product_id":"csi-mystery-3-digit-addition-multiplication-division-2nd-4th-grade","title":"Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 2–5 | The Missing Stationery","description":"\u003cp\u003eAugust and September back to school CSI math worksheets: addition and subtraction with two-digit and three-digit numbers, some early multiplication, and a CSI Mystery Detective story to carry it. On the first morning back, 2nd grade and 3rd grade students find every pencil and crayon gone, and whoever cleared the room left footprints and enough math behind to be named. It is back to school math with a purpose, and the mystery gives a new class a shared job while you learn their names. Print and go, nothing to prepare. Students add along a crayon trail, decode sums with a letter key and color the right arrow forward, losing a suspect each time. Answer keys included.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case: The Missing Stationery\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThere has been an emergency at school. Your students walk into class on the first morning back and every last piece of stationery is gone - pencils, crayons, scissors, the lot. Somebody came in over the holidays while the building was empty and cleared the room out. They left footprints, though, and enough math behind to say exactly who they were.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eAddition along a crayon trail where the running total settles the clue\u003c\/li\u003e\n  \u003cli\u003eChecking worked answers for errors and tallying which are correct\u003c\/li\u003e\n  \u003cli\u003eThree-digit addition decoded through a letter key\u003c\/li\u003e\n  \u003cli\u003eMultiplication used to color the correct circle and arrow forward\u003c\/li\u003e\n  \u003cli\u003eA matching page where the line drawn passes through the letter that matters\u003c\/li\u003e\n  \u003cli\u003eFull color and black-and-white versions of every page\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for the whole case\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eIt is a printable CSI Mystery Detective case: a back to school escape room on paper, with no locks, no apps and nothing to set up. Students work a page of back to school math worksheets, and every answer they get right crosses another suspect off the line-up until one name is left. Detective activities like this one run themselves, because a careless answer sends the description the wrong way and students go back over their own work.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eThe first days back at school, when you want the math to feel like fun\u003c\/li\u003e\n  \u003cli\u003eSeeing what came back with them after the summer\u003c\/li\u003e\n  \u003cli\u003eMath centers, early finishers and independent work\u003c\/li\u003e\n  \u003cli\u003eEmergency sub plans that run themselves\u003c\/li\u003e\n  \u003cli\u003eEnd of year review, when attention is thin and the work still has to happen\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBuilt for 2nd grade and 3rd grade. Second graders usually work the three-digit addition in pairs; third graders can run the case independently inside a lesson. It also suits 4th grade students who need addition and subtraction review in a form that does not feel like going back a year.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love CSI Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eZero prep - print and hand out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking by design, because a wrong answer breaks the deduction\u003c\/li\u003e\n  \u003cli\u003eA first-week activity that still does real math\u003c\/li\u003e\n  \u003cli\u003eWorks as a whole lesson, a center, or a filler for an awkward afternoon\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education for new detective cases, seasonal math activities and updates on discounts and new releases.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52335128248690,"sku":"5799886","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/back-to-school-csi-mystery-detective-grades-2-3-first-week-5799886.jpg?v=1792459172"},{"product_id":"addition-subtraction-multiplication-csi-mystery-presidents-day","title":"Presidents Day CSI Mystery Worksheets | Grades 2–5 | The Missing Hat","description":"\u003cp\u003eFebruary Presidents Day CSI math worksheets that play out as a CSI Mystery Detective case on three-digit addition and multiplication facts, with a missing stovepipe hat and a speech due in an hour. Aimed at 3rd grade, 4th grade and 5th grade, it is a multiplication mystery for the week around Lincoln's birthday and a handy snow day math option too. Both color and black-and-white pages are included and nothing needs cutting. Students follow a trail of stars where an odd or even total settles the clue, decode addition answers through a letter key, and circle letters on a multiplication grid to unscramble the final name, sending one suspect home with every right answer.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case: Help! The Missing Hat\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eToday is the day of the big speech. He is up early, into the favorite suit, breakfast made, teeth cleaned, one last run through the words. He is ready. And the hat - the one everybody would recognize from a hundred yards - is not on the stand where it lives. The speech is in an hour, and somebody in this house has taken it.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eAddition along a trail of stars where an odd or even total settles the clue\u003c\/li\u003e\n  \u003cli\u003eThree-digit addition decoded through a letter key to give a shoe size\u003c\/li\u003e\n  \u003cli\u003eChecking worked answers for errors and tallying which are correct\u003c\/li\u003e\n  \u003cli\u003eMultiplication used to color the correct circle and arrow forward\u003c\/li\u003e\n  \u003cli\u003eCircling letters on a grid using multiplication answers, then unscrambling them\u003c\/li\u003e\n  \u003cli\u003eFull color and black-and-white versions of every page\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for the whole case\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mystery Detective case is a printable investigation your class solves with math. It runs like a math escape room - no locks, no app, no prep - except that instead of opening a box, every correct answer rules one suspect out of the line-up until a single name is left. That is what separates detective activities from ordinary math worksheets: the arithmetic has to be right or the case will not close, so students check their own work. It is a math activity that carries a whole lesson, and it works just as well in math centers or as a sub plan.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003ePresidents Day in February, alongside your history work\u003c\/li\u003e\n  \u003cli\u003eThe days around a holiday, when you still want real math done\u003c\/li\u003e\n  \u003cli\u003eMath centers, early finishers and independent work\u003c\/li\u003e\n  \u003cli\u003eEmergency sub plans that run themselves\u003c\/li\u003e\n  \u003cli\u003eEnd of year review, when attention is thin and the work still has to happen\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBuilt for 3rd grade, 4th grade and 5th grade. Third graders may want their times tables to hand for the grid page; fourth and fifth graders run the case independently inside a lesson. It also suits 2nd grade students who are ahead and want something with more thinking in it.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love CSI Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eZero prep - print and hand out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking by design, because a wrong answer breaks the deduction\u003c\/li\u003e\n  \u003cli\u003eA Presidents Day activity that still does real math\u003c\/li\u003e\n  \u003cli\u003eWorks as a whole lesson, a center, or a filler for an awkward afternoon\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education for new detective cases, seasonal math activities and updates on discounts and new releases.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52346750501234,"sku":"5246705","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/presidents-day-csi-mystery-detective-february-grades-3-5-5246705.jpg?v=1792460005"},{"product_id":"valentines-day-csi-mystery-grades-3-5","title":"Valentine’s Day CSI Mystery Worksheets | Grades 2–5 | Love Bug Wizard","description":"\u003cp\u003eValentines Day math addition and multiplication CSI Mystery worksheets for February - a no prep CSI Mystery Detective case for 3rd grade, 4th grade and 5th grade, built on 3 digit addition and the multiplication facts. The math worksheets come in color and black-and-white with answer keys, and every correct answer rules one suspect out of the line-up until one name is left. The case: the whole school has gone kind - too kind, all at once - so somebody has been through it with a wand, and the class has to work out which wizard. It plays like a paper-based escape room: a trail of hearts, a letter key to decode, a grid to unscramble.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case: Help! The Love Bugs\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eIt is Valentines Day. Not your favorite day of the year, but there is something to be said for a building full of people being unusually nice to each other. Random acts of kindness everywhere. Then it tips over into something else - too nice, all at once, all day - and it becomes clear somebody has been at the school with a wand. Your students need to work out which wizard.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eAddition along a trail of hearts where an odd or even total settles the clue\u003c\/li\u003e\n  \u003cli\u003eThree-digit addition decoded through a letter key\u003c\/li\u003e\n  \u003cli\u003eChecking worked answers for errors and tallying which are correct\u003c\/li\u003e\n  \u003cli\u003eCircling letters on a grid using multiplication answers, then unscrambling them\u003c\/li\u003e\n  \u003cli\u003eMultiplication used to color the correct heart and arrow forward\u003c\/li\u003e\n  \u003cli\u003eFull color and black-and-white versions of every page\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for the whole case\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mystery Detective case is a printable investigation your class solves with math. It runs like a math escape room with the locks taken out - no app, no boxes, nothing to prepare - and rather than opening something, every correct answer rules one suspect out of the line-up until a single name is left. That is the difference between detective activities and ordinary math worksheets: the arithmetic decides the outcome, so students check their own work first. As a math activity it fills a lesson, a center, or a sub plan.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eValentines Day in February, when a normal worksheet will not hold them\u003c\/li\u003e\n  \u003cli\u003eAddition and multiplication review before or after a unit test\u003c\/li\u003e\n  \u003cli\u003eMath centers, early finishers and independent work\u003c\/li\u003e\n  \u003cli\u003eEmergency sub plans that run themselves\u003c\/li\u003e\n  \u003cli\u003eEnd of year review, when attention is thin and the work still has to happen\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBuilt for 3rd grade, 4th grade and 5th grade. Third graders may want their times tables to hand for the grid page; fourth and fifth graders run the case independently inside a lesson. It also suits 2nd grade students who are ahead and want something with more thinking in it.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love CSI Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eZero prep - print and hand out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking by design, because a wrong answer breaks the deduction\u003c\/li\u003e\n  \u003cli\u003eA Valentines activity that still does real math\u003c\/li\u003e\n  \u003cli\u003eWorks as a whole lesson, a center, or a filler for an awkward afternoon\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education for new detective cases, seasonal math activities and updates on discounts and new releases.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52347043217778,"sku":"5146409","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/valentines-day-csi-mystery-detective-february-grades-3-5-5146409.jpg?v=1792460272"},{"product_id":"christmas-csi-mystery-grades-2-5","title":"Christmas CSI Mystery Worksheets | Grades 2–5 | Who Stole the Sleigh?","description":"\u003cp\u003eDecember is when Christmas addition and subtraction CSI math worksheets earn their keep, and Help! Santa's Sleigh gives them a crime scene. This Christmas CSI Mystery Detective case runs on two-digit and three-digit addition and subtraction with regrouping, plus a taste of multiplication, wrapped in a North Pole mystery for 2nd grade and 3rd grade. Helpers on double shifts, a record year for good children, and days before Christmas somebody at the Pole sabotaged the sleigh. Each correct answer strikes a suspect off the line-up until one remains, from a trail of presents to a decoration colored by the right product. Print in color or black and white, answer keys included, no prep.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case: Help! Santa's Sleigh\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eIt has been another long year at the North Pole, and a record number of children have somehow managed to stay good the whole way through. The helpers have been working double shifts to keep up. And now, days out, something has happened to the sleigh. Somebody at the Pole is responsible, and your students have to work out which one before the whole thing is called off.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eAddition along a trail of presents where the running total settles the clue\u003c\/li\u003e\n  \u003cli\u003eReading letters off a map with a key to decode a message\u003c\/li\u003e\n  \u003cli\u003eThree-digit addition decoded through a letter key\u003c\/li\u003e\n  \u003cli\u003eA matching page where the line drawn passes through the letter that matters\u003c\/li\u003e\n  \u003cli\u003eMultiplication used to color the correct decoration and arrow forward\u003c\/li\u003e\n  \u003cli\u003eFull color and black-and-white versions of every page\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for the whole case\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mystery Detective case is a printable investigation your class solves with math. It runs like a math escape room with the locks taken out - no app, no boxes, nothing to prepare - and instead of opening something, every correct answer rules one suspect out of the line-up until a single name is left. That is the difference between detective activities and ordinary math worksheets: the arithmetic decides the outcome, so students check their own work first. As a math activity it fills a lesson, a center, or a sub plan.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eThe last weeks of December, when a normal worksheet will not hold them\u003c\/li\u003e\n  \u003cli\u003eChristmas parties and the days either side of them\u003c\/li\u003e\n  \u003cli\u003eMath centers, early finishers and independent work\u003c\/li\u003e\n  \u003cli\u003eEmergency sub plans that run themselves\u003c\/li\u003e\n  \u003cli\u003eWhole-class detective sessions, small groups or partner work\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBuilt for 2nd grade and 3rd grade. Second graders usually pair up on the three-digit addition; third graders run the case independently. It also suits 4th grade students who need addition and subtraction review in a form that does not look like going back a year.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love CSI Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eZero prep - print and hand out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking by design, because a wrong answer breaks the deduction\u003c\/li\u003e\n  \u003cli\u003eA December activity that still does real math\u003c\/li\u003e\n  \u003cli\u003eWorks as a whole lesson, a center, or a filler for an awkward afternoon\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education for new detective cases, seasonal math activities and updates on discounts and new releases.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52347057078642,"sku":"5070687","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/christmas-santas-sleigh-csi-mystery-detective-grades-2-3-5070687.jpg?v=1792459386"},{"product_id":"thanksgiving-csi-mystery-grades-2-5","title":"Thanksgiving CSI Mystery Worksheets | Grades 2–5 | The Missing Turkey","description":"\u003cp\u003eNovember means Thanksgiving, and this Thanksgiving math pack for 2nd grade and 3rd grade turns the week before the feast into a Thanksgiving mystery worth solving. It is a CSI Mystery Detective case built on two-digit addition and subtraction, with a taste of early multiplication and Thanksgiving subtraction with regrouping along the way. It plays like a paper-based escape room: each correct answer crosses one suspect off the line-up until the guest who raided the table stands alone. Full color and black-and-white turkey CSI math worksheets, answer keys, print and go. Students add along a turkey trail, decode letters from a Thanksgiving map and check worked answers before dinner is served.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case: Thanksgiving\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThanksgiving is nearly here. Aunts and uncles have flown in from the other side of the country, the table is set, and the whole family is finally in one place. Then something goes missing from the feast. It was someone in this house, or someone who was invited, and your students have until dinner to work out which one of them it was.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eAddition along a turkey trail where the running total settles the clue\u003c\/li\u003e\n  \u003cli\u003eReading letters off a Thanksgiving map with a key to decode a message\u003c\/li\u003e\n  \u003cli\u003eMultiplication used to color the correct acorn and arrow forward\u003c\/li\u003e\n  \u003cli\u003eTwo-digit addition decoded through a letter key\u003c\/li\u003e\n  \u003cli\u003eChecking worked answers for errors and tallying which are correct\u003c\/li\u003e\n  \u003cli\u003eFull color and black-and-white versions of every page\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for the whole case\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mystery Detective case is math practice with a culprit at the end of it. The class works the page, each correct answer rules a suspect out, and the case closes on the last name left. It runs like a math escape room with the hardware removed - no locks, no app, no prep. It is far harder to coast through than ordinary math worksheets, because the arithmetic has to hold or nothing lines up. Use it as a full math activity, in math centers, or as detective activities for early finishers.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eThanksgiving week in November, when a normal worksheet will not hold them\u003c\/li\u003e\n  \u003cli\u003eThe days before a holiday, when you still want real math done\u003c\/li\u003e\n  \u003cli\u003eMath centers, early finishers and independent work\u003c\/li\u003e\n  \u003cli\u003eEmergency sub plans that run themselves\u003c\/li\u003e\n  \u003cli\u003eWhole-class detective sessions, small groups or partner work\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBuilt for 2nd grade and 3rd grade. Second graders usually work the trail pages in pairs; third graders can run the whole case on their own. It also suits 4th grade students who need addition and subtraction review in a form that does not feel like going back a year.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love CSI Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eZero prep - print and hand out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking by design, because a wrong answer breaks the deduction\u003c\/li\u003e\n  \u003cli\u003eA holiday activity that still does real math\u003c\/li\u003e\n  \u003cli\u003eWorks as a whole lesson, a center, or a filler for an awkward afternoon\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education for new detective cases, seasonal math activities and updates on discounts and new releases.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":52522795565426,"sku":"5003849","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/the-missing-turkey-thanksgiving-mystery-detective-grades-3-5-5003849.jpg?v=1792460271"},{"product_id":"addition-subtraction-csi-mystery-worksheets-grades-2-3-alien-invasion","title":"Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 2–3 | Alien Invasion","description":"\u003cp\u003eCSI Mystery Detective goes interplanetary: an alien invasion that 2nd grade and 3rd grade students solve with addition, subtraction and rounding, where only correct answers reveal which alien is behind it. It begins as an ordinary September school day with a dot growing bigger on the horizon, and ends with students working two-digit and three-digit addition, rounding to the nearest ten and cracking a number sequence to shrink the suspect line-up. These CSI math worksheets come in full color and black and white with answer keys, ready the moment they leave the printer. Students spot wrong answers, keep a tally, follow linked clues and cross off suspects until one alien remains in the mystery.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case: Alien Invasion\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eIt starts as an ordinary school day. Your students are at their desks, looking out at a calm sky, when a tiny dot appears on the horizon and starts getting bigger. By the time anyone thinks to shout, it is close enough to see clearly, and the school day is over. Somewhere out there is one alien responsible for all of this, and the only way to identify it is to work the math and narrow the field.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eSpotting correct and incorrect answers and marking them off against a tally\u003c\/li\u003e\n  \u003cli\u003eTwo-digit and three-digit addition worked through a chain of linked clues\u003c\/li\u003e\n  \u003cli\u003eRounding numbers to the nearest ten to shade the right answer\u003c\/li\u003e\n  \u003cli\u003eA number sequence puzzle that builds to one final figure\u003c\/li\u003e\n  \u003cli\u003eA suspect line-up that narrows every time a clue is solved\u003c\/li\u003e\n  \u003cli\u003eFull color and black-and-white versions of every page\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for the whole case\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mystery Detective case is a printable investigation your class solves with math. It runs like a math escape room with the locks taken out - no app, no props, no prep - and rather than opening a box, every correct answer rules one suspect out of the line-up until a single name is left. That is the difference between detective activities and ordinary math worksheets: the arithmetic decides the outcome, so students check their own work before they hand it in. As a math activity it fills a lesson, a center, or a sub plan.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eBack-to-school weeks, when you want the math to feel like fun rather than testing\u003c\/li\u003e\n  \u003cli\u003eMath centers, early finishers and independent work\u003c\/li\u003e\n  \u003cli\u003eEmergency sub plans that run themselves\u003c\/li\u003e\n  \u003cli\u003eEnd of year review, when attention is thin and the work still has to happen\u003c\/li\u003e\n  \u003cli\u003eWhole-class detective sessions, small groups or partner work\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBuilt for 2nd grade and 3rd grade. Second graders usually work it in pairs and take their time over the three-digit addition; third graders can run the case independently and finish inside a lesson. It also suits 4th grade students who need addition, subtraction and rounding review in a form that does not look like remedial work.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love CSI Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eZero prep - print and hand out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking by design, because a wrong answer breaks the deduction\u003c\/li\u003e\n  \u003cli\u003eRepeatable practice students ask to do again\u003c\/li\u003e\n  \u003cli\u003eWorks as a whole lesson, a center, or a filler for an awkward afternoon\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education for new detective cases, seasonal math activities and updates on discounts and new releases.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61951206228338,"sku":"3807824","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/alien-invasion-csi-mystery-detective-addition-subtraction-grades-2-3-3807824.jpg?v=1792459155"},{"product_id":"addition-subtraction-csi-mystery-worksheets-grades-3-5-haunted-halloween","title":"Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 3–5 | Haunted Halloween","description":"\u003cp\u003eHaunted Halloween CSI math worksheets for 2nd grade and 3rd grade: 2 digit addition and subtraction with regrouping, ready for October. Inside the CSI Mystery Detective case, the candy the teacher promised the whole class has vanished from the desk - not eaten, gone, with a cold draft down the hallway nobody can explain. The mystery is which ghost took it. Each correct answer rules one ghost out of the line-up, so students keep working because they want the name. Color and black-and-white versions, answer keys, nothing to cut. They check worked answers for errors, read a map key, and follow a subtraction path where the running total settles the clue.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case: Haunted Halloween\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eHalloween is finally here and your teacher has promised sweets for the whole class. Everybody is in a good mood, nobody is working, and then the sweets are gone. Not eaten - gone, along with a cold draught down the corridor that nobody can explain. There is a ghost in this school, and your students have to work out exactly which one.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eChecking worked answers for errors and tallying which are correct\u003c\/li\u003e\n  \u003cli\u003eReading letters off a map with a key to decode a clue\u003c\/li\u003e\n  \u003cli\u003eMulti-step problems where the last answers unlock a code chart\u003c\/li\u003e\n  \u003cli\u003eSubtraction along a path where the running total settles the clue\u003c\/li\u003e\n  \u003cli\u003eSubtraction problems used to color the correct arrow forward\u003c\/li\u003e\n  \u003cli\u003eFull color and black-and-white versions of every page\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for the whole case\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eIn a CSI Mystery Detective case, the suspect list does the job an answer key usually does. Students solve, each correct answer clears one name, and the last one standing is the culprit. It is a math escape room made of paper - no locks, no app, nothing to cut or set up. That is also what makes it self-checking where ordinary math worksheets are not: bad arithmetic leaves a description that fits nobody. It runs as a whole math activity, in math centers, or as detective activities for early finishers.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eHalloween week in October, when a normal worksheet will not hold them\u003c\/li\u003e\n  \u003cli\u003eThe days before a holiday, when you still want real math done\u003c\/li\u003e\n  \u003cli\u003eMath centers, early finishers and independent work\u003c\/li\u003e\n  \u003cli\u003eEmergency sub plans that run themselves\u003c\/li\u003e\n  \u003cli\u003eEnd of year review, when attention is thin and the work still has to happen\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBuilt for 2nd grade and 3rd grade. Second graders usually run it comfortably; third graders finish inside a lesson and often ask for another. It also suits 4th grade students who need 2 digit addition and subtraction review in a form that does not feel like going back a year.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love CSI Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eZero prep - print and hand out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking by design, because a wrong answer breaks the deduction\u003c\/li\u003e\n  \u003cli\u003eA Halloween activity that still does real math\u003c\/li\u003e\n  \u003cli\u003eWorks as a whole lesson, a center, or a filler for an awkward afternoon\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education for new detective cases, seasonal math activities and updates on discounts and new releases.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61951262720370,"sku":"4074188","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/haunted-jack-o-lantern-csi-mystery-detective-halloween-grades-2-4-4074188.jpg?v=1792459386"},{"product_id":"addition-subtraction-csi-mystery-worksheets-grades-2-3-jungle-juice-fever","title":"Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 2–3 | Jungle Juice Fever","description":"\u003cp\u003eCSI Mystery Detective case on addition and subtraction within 100 and missing numbers to 100, delivered as CSI math worksheets about a jungle camp that something raided in the dark this October. Built for 2nd grade and 3rd grade, it turns a plain addition and subtraction mystery into a hunt for whatever dug to the bottom of the backpack, because the culprit left just enough behind to be identified. Every page prints in color or black and white, and answer keys are included. Students complete number sequences to reveal the next part of the description, work linked questions down to one final number and use subtraction clues, shortening the line-up with every right answer.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case: Jungle Juice Fever\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eYour students wake up in the jungle after a long night, starving. They climb out of the sleeping bag, reach for the backpack and dig right down to the bottom, because the good stuff was buried where nothing could get at it. It is not there. Something came through the camp in the dark, and it left just enough behind to be identified.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eNumber sequences completed to reveal the next part of the description\u003c\/li\u003e\n  \u003cli\u003eAddition and subtraction within 100 across the clue pages\u003c\/li\u003e\n  \u003cli\u003eA sequence of linked questions that builds to one final number\u003c\/li\u003e\n  \u003cli\u003eSubtraction problems used to settle a clue about the culprit\u003c\/li\u003e\n  \u003cli\u003eA suspect line-up that narrows every time a clue is solved\u003c\/li\u003e\n  \u003cli\u003eFull color and black-and-white versions of every page\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for the whole case\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mystery Detective case turns a page of math into evidence. Students solve, each correct answer strikes one name off the suspect list, and the case closes on the last one standing. There is nothing to unlock, download or prepare - it is a math escape room made of paper. Detective activities police themselves in a way ordinary math worksheets cannot: an error leaves a culprit nobody can arrest, so the class goes back over it. A math activity that carries a lesson, a center rotation, or a sub plan.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eAddition and subtraction review before or after a unit test\u003c\/li\u003e\n  \u003cli\u003eBack-to-school weeks and end of year review\u003c\/li\u003e\n  \u003cli\u003eMath centers, early finishers and independent work\u003c\/li\u003e\n  \u003cli\u003eEmergency sub plans that run themselves\u003c\/li\u003e\n  \u003cli\u003eA jungle, rainforest or animals topic week, alongside reading or science work\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBuilt for 2nd grade and 3rd grade. Second graders usually run it comfortably with a little support on the sequence page; third graders finish inside a lesson. It also suits 4th grade students who need addition and subtraction review in a form that does not look like going back a year.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love CSI Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eZero prep - print and hand out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking by design, because a wrong answer breaks the deduction\u003c\/li\u003e\n  \u003cli\u003ePractice students ask to do again\u003c\/li\u003e\n  \u003cli\u003eWorks as a whole lesson, a center, or a filler for an awkward afternoon\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education for new detective cases, seasonal math activities and updates on discounts and new releases.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61951285526898,"sku":"3765647","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/jungle-juice-fever-mystery-detective-addition-subtraction-grades-2-3-3765647.jpg?v=1792459171"},{"product_id":"addition-subtraction-csi-mystery-grades-2-5-my-teacher-is-an-alien-back-to-school","title":"Back to School Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 2–5 | My Teacher is an Alien","description":"\u003cp\u003eBack to school addition and subtraction CSI math worksheets with a twist: this CSI Mystery Detective case asks students to prove their new teacher is an alien. Skin, eyes, ears, number of arms, every line of the description comes from a problem within 200, which makes it a sharp August and September math activity for 3rd grade and 4th grade. Color and black-and-white versions are both included, so the only setup is pressing print. Students color the correct arrow to the next clue, decode a message off a space map, and follow an odd-or-even path, ruling out one suspect at a time until the mystery is closed. Answer keys cover the whole case.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case: My Teacher is an Alien\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eYou have always been a bit nervous around this teacher. The clothes are too perfect. The laugh is too loud, and always half a second late. The smile does not quite reach anywhere. Everybody else says you are imagining it, so the only way to settle it is evidence: the skin, the eyes, the ears, the number of arms, worked out one math problem at a time.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eAddition problems used to color the correct arrow to the next clue\u003c\/li\u003e\n  \u003cli\u003eChecking worked answers for errors and tallying which are correct\u003c\/li\u003e\n  \u003cli\u003eReading letters off a space map with a key to decode a message\u003c\/li\u003e\n  \u003cli\u003eAddition along a path where an odd or even final total decides the answer\u003c\/li\u003e\n  \u003cli\u003eA matching page where the line drawn passes through the letter that matters\u003c\/li\u003e\n  \u003cli\u003eFull color and black-and-white versions of every page\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for the whole case\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eYour students get a crime, a line-up and a page of math worksheets - nothing else. The answers do the eliminating: one right answer, one suspect gone, until only the culprit is left. That is a CSI Mystery Detective case, and it works like a math escape room without the locks or the login. It also marks itself, which a practice page never does, because a wrong answer leaves a description matching nobody. Run it as a whole math activity, in math centers, or as detective activities for early finishers.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eThe first weeks back at school, when you want the math to feel like fun\u003c\/li\u003e\n  \u003cli\u003eMath centers, early finishers and independent work\u003c\/li\u003e\n  \u003cli\u003eEmergency sub plans that run themselves\u003c\/li\u003e\n  \u003cli\u003eEnd of year review, when attention is thin and the work still has to happen\u003c\/li\u003e\n  \u003cli\u003eWhole-class detective sessions, small groups or partner work\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBuilt for 3rd grade and 4th grade. Third graders usually run it comfortably on their own; fourth graders finish it inside a lesson and often ask for another. It also suits 2nd grade students who are ahead and need something with more thinking in it than extra practice.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love CSI Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eZero prep - print and hand out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking by design, because a wrong answer breaks the deduction\u003c\/li\u003e\n  \u003cli\u003eA back-to-school activity that still does real math\u003c\/li\u003e\n  \u003cli\u003eWorks as a whole lesson, a center, or a filler for an awkward afternoon\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education for new detective cases, seasonal math activities and updates on discounts and new releases.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61951738315122,"sku":"3990720","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/my-teacher-is-an-alien-csi-mystery-detective-back-to-school-grades-3-4-3990720.jpg?v=1792459386"},{"product_id":"pancake-day-addition-subtraction-csi-mystery-grades-2-5-the-half-eaten-pancake","title":"Pancake Day Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 2–5 | The Half-Eaten Pancake","description":"\u003cp\u003eFebruary and March bring Pancake Day, Shrove Tuesday and Lent, and these CSI math worksheets turn all three into a CSI Mystery Detective case on addition, subtraction and number sequences. Mrs Wilson has made her pancakes every year and never written the recipe down, so when one turns up half eaten before anyone was meant to start, somebody could not wait. 3rd grade, 4th grade and 5th grade students add and subtract three-digit and four-digit numbers, follow linked clues to one final number, and unscramble a word that only resolves once the earlier answers are right, eliminating a suspect at each step. Prints in color or black and white, with answer keys for the whole mystery.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case: The Half Eaten Pancake\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003ePancake Day is here and the whole school is looking forward to it, mostly because of Mrs Wilson. She has been making her pancakes for this day every year for as long as anyone can remember, and the recipe has never been written down. This morning one of them has been found half eaten, well before anybody was supposed to have started. Somebody could not wait.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eDeciding which number problems are correct and counting up the results\u003c\/li\u003e\n  \u003cli\u003eA sequence of linked clues that builds to one final number\u003c\/li\u003e\n  \u003cli\u003eAddition and subtraction with three-digit and four-digit numbers\u003c\/li\u003e\n  \u003cli\u003eChecking worked answers for errors and tallying which are correct\u003c\/li\u003e\n  \u003cli\u003eA word unscramble that only resolves once the earlier answers are right\u003c\/li\u003e\n  \u003cli\u003eFull color and black-and-white versions of every page\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for the whole case\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mystery Detective case works the way a math escape room works, except the exit is a name rather than a lock. The class solves a page of math worksheets, each correct answer removes a suspect, and the last one left is the arrest. There is no app, no cutting and no prep. What it has that a practice page does not is a built-in check: wrong arithmetic leaves a description matching nobody. A math activity for a lesson, for math centers, or as detective activities for early finishers.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eShrove Tuesday and the start of Lent, in February or March\u003c\/li\u003e\n  \u003cli\u003eThe days before a holiday, when you still want real math done\u003c\/li\u003e\n  \u003cli\u003eMath centers, early finishers and independent work\u003c\/li\u003e\n  \u003cli\u003eEmergency sub plans that run themselves\u003c\/li\u003e\n  \u003cli\u003eEnd of year review, when attention is thin and the work still has to happen\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBuilt for 3rd grade, 4th grade and 5th grade. Third graders usually pair up on the four-digit pages; fourth and fifth graders run the case independently inside a lesson. It also suits 2nd grade students who are ahead and want something with more thinking in it.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love CSI Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eZero prep - print and hand out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking by design, because a wrong answer breaks the deduction\u003c\/li\u003e\n  \u003cli\u003eA seasonal activity that still does real math\u003c\/li\u003e\n  \u003cli\u003eWorks as a whole lesson, a center, or a filler for an awkward afternoon\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education for new detective cases, seasonal math activities and updates on discounts and new releases.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61952231539058,"sku":"3595082","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/pancake-day-addition-subtraction-math-worksheets-shrove-tuesday-cover-3595082.jpg?v=1792460001"},{"product_id":"st-patricks-day-addition-subtraction-csi-mystery-grades-2-5-the-hidden-pot-of-gold","title":"St. Patrick's Day Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 2–5 | The Hidden Pot of Gold","description":"\u003cp\u003eSt Patricks Day addition and subtraction CSI math worksheets for March, wrapped in a CSI Mystery Detective case your class will want to finish. The Hidden Pot of Gold mystery sends 2nd grade and 3rd grade students inside a leprechaun's hideout, where every correct sum within 100 rules one suspect out of the line-up and the last name standing is the culprit. It is fun math practice with a reason to be accurate, timed for the week of the 17th. Students read a map through a letter key, add along a trail of gold pots, check worked answers for errors and color the right shamrock forward. Color and black-and-white pages plus answer keys, nothing to cut.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case: The Hidden Pot of Gold\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eSt Patricks Day falls on the 17th of March, and the stories that come with it are older than anyone can trace. A leprechaun is a small, sharp, well-dressed fairy from Irish folklore, and it keeps its gold somewhere nobody has ever found. Your students have got closer than anyone: they are inside, and there is one route through to the pot that the math will give them.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eReading letters off a map with a key to decode the first direction\u003c\/li\u003e\n  \u003cli\u003eAddition along a trail of pots of gold, with the running total settling the clue\u003c\/li\u003e\n  \u003cli\u003eChecking worked answers for errors and tallying which are correct\u003c\/li\u003e\n  \u003cli\u003eAddition problems used to color the correct shamrock and arrow forward\u003c\/li\u003e\n  \u003cli\u003eAddition decoded through a letter key to find the final room\u003c\/li\u003e\n  \u003cli\u003eFull color and black-and-white versions of every page\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for the whole case\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eDeduction on paper, powered by math - that is a CSI Mystery Detective case. Your class gets a crime and a line-up, the math worksheets supply the evidence, and every correct answer removes one suspect until a single name is left. It is a math escape room without the locks, the login or the prep. The advantage over a practice page is that the arithmetic has to hold or the case will not close. Use it as a whole math activity, in math centers, or as detective activities for early finishers.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eSt Patricks Day in March, when a normal worksheet will not hold them\u003c\/li\u003e\n  \u003cli\u003eAddition and subtraction review before or after a unit test\u003c\/li\u003e\n  \u003cli\u003eMath centers, early finishers and independent work\u003c\/li\u003e\n  \u003cli\u003eEmergency sub plans that run themselves\u003c\/li\u003e\n  \u003cli\u003eEnd of year review, when attention is thin and the work still has to happen\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBuilt for 2nd grade and 3rd grade. Second graders run it comfortably with a little support on the trail page; third graders finish inside a lesson. It also suits 4th grade students who need addition and subtraction review in a form that does not look like going back a year.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love CSI Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eZero prep - print and hand out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking by design, because a wrong answer breaks the deduction\u003c\/li\u003e\n  \u003cli\u003eA St Patricks Day activity that still does real math\u003c\/li\u003e\n  \u003cli\u003eWorks as a whole lesson, a center, or a filler for an awkward afternoon\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education for new detective cases, seasonal math activities and updates on discounts and new releases.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61952454754674,"sku":"4403124","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/st-patricks-day-hidden-pot-of-gold-csi-mystery-detective-grades-2-5-4403124.jpg?v=1792460140"},{"product_id":"easter-addition-subtraction-csi-mystery-grades-2-5-the-easter-egg-hunt","title":"Easter Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 2–5 | The Easter Egg Hunt","description":"\u003cp\u003eEaster Egg Hunt CSI math worksheets for addition, subtraction and skip counting, ready for March and April with a CSI Mystery Detective case behind them. Most of the eggs vanished before the hunt started, and somebody knew exactly where to look. Your 2nd grade and 3rd grade students rule one suspect out with every correct answer until the culprit is the only name left. It plays like a paper-based escape room without any of the setup: print in color or black and white and the mystery runs itself. Students highlight the correct sums, color a skip-counting maze in tens, and build an addition pyramid whose odd and even answers settle the last clue. Answer keys included.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case: The Easter Egg Hunt\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eEaster has arrived at school and the Annual Easter Egg Hunt is the only thing anyone is talking about. Every year the principal hands one trusted person the job of hiding the eggs around the grounds. This year they were hidden, and then most of them were gone before the hunt even started. Somebody knew exactly where to look, and your students have the math to work out who.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eSpotting which addition and subtraction problems are correct and highlighting them\u003c\/li\u003e\n  \u003cli\u003eSkip counting in tens through a maze, coloring each number on the way\u003c\/li\u003e\n  \u003cli\u003eA sequence of linked questions that builds to one final number\u003c\/li\u003e\n  \u003cli\u003eNumber problems that reveal the next letter of the description\u003c\/li\u003e\n  \u003cli\u003eAn addition pyramid where the count of odd and even answers settles the clue\u003c\/li\u003e\n  \u003cli\u003eFull color and black-and-white versions of every page\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for the whole case\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eStudents are the detectives and math is the only evidence they get. That is the whole of a CSI Mystery Detective case: work the page, rule a suspect out with each correct answer, and close the case on the last name standing. It runs as a math escape room with no locks, no app and no prep at all. It is also self-marking in practice, which math worksheets are not - a wrong answer produces a culprit who cannot exist. Use it as a math activity, in math centers, or as a sub plan.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eEaster week in March or April, when a normal worksheet will not hold them\u003c\/li\u003e\n  \u003cli\u003eThe days before a holiday, when you still want real math done\u003c\/li\u003e\n  \u003cli\u003eMath centers, early finishers and independent work\u003c\/li\u003e\n  \u003cli\u003eEmergency sub plans that run themselves\u003c\/li\u003e\n  \u003cli\u003eEnd of year review, when attention is thin and the work still has to happen\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBuilt for 2nd grade and 3rd grade. Second graders usually need a little support on the sequence page; third graders run the whole case on their own. It also suits 4th grade students who need addition, subtraction and skip counting review without it feeling like going back a year.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love CSI Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eZero prep - print and hand out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking by design, because a wrong answer breaks the deduction\u003c\/li\u003e\n  \u003cli\u003eAn Easter activity that still does real math\u003c\/li\u003e\n  \u003cli\u003eWorks as a whole lesson, a center, or a filler for an awkward afternoon\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education for new detective cases, seasonal math activities and updates on discounts and new releases.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61952461701490,"sku":"3664965","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/easter-egg-hunt-mystery-detective-addition-subtraction-regrouping-3664965.jpg?v=1792459543"},{"product_id":"3-digit-addition-with-regrouping-mystery-detective-worksheets-grades-2-5-christmas-theme","title":"3-Digit Addition with Regrouping | Mystery Detective Worksheets | Grades 2–5 | Christmas Theme","description":"\u003cp\u003eChristmas 3 digit addition with regrouping worksheets for 2nd grade and 3rd grade, five math cases, each a Mystery Detective page of column sums. Print and go with full answer keys: math worksheets and CSI Mini Mystery Detective cases in one, no prep, for morning work, math centers, early finishers, homework and sub plans. The whole pack is built around a school Christmas, from the secret Santa to the staffroom lunch, so 2nd grade and 3rd grade students get 3 digit addition with regrouping practice that feels like part of the season. Use it as Christmas math activities for the last fortnight, a December math center or a self-marking homework set.\u003c\/p\u003e\n\n\u003cp\u003eThe last fortnight before the Christmas break is when a secret Santa to unmask turns a page of sums into the addition practice a class asks for. Because each total has to match a clue, the pages mark themselves. One CSI Mini Mystery Detective math case a day covers the fortnight's mornings.\u003c\/p\u003e\n\u003cp\u003eAn elf has left a present, somebody made the teachers a Christmas lunch, and the family needs someone to carve the turkey. Students carry across the columns to find each total, then cross off the clue it matches. It keeps addition practice going through the last weeks before break.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChristmas Turkey\u003c\/strong\u003e - who's carving the turkey\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSecret Santa\u003c\/strong\u003e - a gift on the teacher's desk\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChristmas Kindness\u003c\/strong\u003e - good deeds at Christmas\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChristmas Lunch\u003c\/strong\u003e - lunch made for the teachers\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChristmas Elf\u003c\/strong\u003e - who the elf's present is for\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFive Christmas cases of 3 digit addition with regrouping\u003c\/li\u003e\n  \u003cli\u003eBlack and white copies\u003c\/li\u003e\n  \u003cli\u003eAn answer key for every case\u003c\/li\u003e\n  \u003cli\u003eProblems laid out in columns\u003c\/li\u003e\n  \u003cli\u003eA teacher instruction page\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA CSI Mini Mystery Detective puts a short Christmas story, a set of addition problems and some clue lists on one page. Students cross off the clues their answers match. The clues that remain solve the case.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThese are for December. 2nd graders can use them at the end of the addition unit, and 3rd graders as review. They work as homework, early finisher work, sub plans or a class party activity.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eBest for 2nd grade and 3rd grade.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eChristmas stories\u003c\/li\u003e\n  \u003cli\u003eRegrouping in every problem\u003c\/li\u003e\n  \u003cli\u003eNo prep\u003c\/li\u003e\n  \u003cli\u003eStudents can check their own totals\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWant more cases like these?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61955246948722,"sku":"5027229","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/christmas-3-digit-addition-with-regrouping-worksheets-2nd-3rd-grade-5027229.jpg?v=1792462233"},{"product_id":"3-digit-addition-with-regrouping-mystery-detective-worksheets-grades-2-5-new-year-theme","title":"3-Digit Addition with Regrouping | Mystery Detective Worksheets | Grades 2–5 | New Year Theme","description":"\u003cp\u003eNew Years 3 digit addition with regrouping worksheets for 2nd grade, 3rd grade and 4th grade: five January math activities, each a Mystery Detective case with sixteen column sums. Print and go with full answer keys and a black and white set, no prep, for math centers, morning work, early finishers, homework and sub plans in the first week of the new year. Somebody set the party popper off early, somebody sang the wrong words to Auld Lang Syne and the countdown is one number short, and every correct total takes a suspect off the list while a missed carry matches nobody, which is how one CSI Mini Mystery Detective download pulls three digit carrying out of the holiday rust.\u003c\/p\u003e\n\n\u003cp\u003eThree digit column addition is the skill worth bringing straight back after a holiday, and the first week back is exactly when this set shines. A case gives the practice a reason to exist, and the marking is student-led, so students find their own carrying slips as they go. It is the bigger sister of the 2 digit New Year pack, with the same party, harder math and the same Mystery Detective rules.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eParty Popper - who set it off early\u003c\/li\u003e\n  \u003cli\u003eNew Year Gift - the gift nobody owns up to\u003c\/li\u003e\n  \u003cli\u003eAuld Lang Syne - working out who sang what\u003c\/li\u003e\n  \u003cli\u003eNew Year Countdown - a count that does not add up\u003c\/li\u003e\n  \u003cli\u003eNew Year Party - the last case of the night\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eFive color case pages, sixteen addition problems on each\u003c\/li\u003e\n  \u003cli\u003eThe same five cases again in black and white\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for all five cases\u003c\/li\u003e\n  \u003cli\u003eA color in page for early finishers\u003c\/li\u003e\n  \u003cli\u003eA teacher instruction page, print and go with nothing to prepare\u003c\/li\u003e\n  \u003cli\u003eThree digit addition with regrouping throughout\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eOne printed page holding one crime and the clue list that solves it. Each clue carries a number, the sixteen sums on the page produce those numbers, and a correct total knocks a clue out. Work to the last question and a single suspect is left standing. Get a column wrong and nothing matches, which sends a student back over their working before you ever see it.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eReach for this in the first days back in January, once three digit addition has been taught and simply needs keeping warm. It works as homework over the break, as a January center, and as a set to leave for a substitute. Use it for math centers, morning work, early finishers, homework, sub plans and homeschool lessons, with a whole class, a small group or one student.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWritten for 2nd grade, 3rd grade and 4th grade. Fifth graders who still need column addition firmed up get plenty out of it, and confident second graders manage it with a little support.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eA wrong total matches no clue, so students catch their own slips\u003c\/li\u003e\n  \u003cli\u003eColor and black and white are both in the download\u003c\/li\u003e\n  \u003cli\u003eA color in page for whoever finishes first\u003c\/li\u003e\n  \u003cli\u003eFive cases covers the whole first week back\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eLove this resource?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no prep math activities, and detective themed printables for elementary classrooms.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61955266675058,"sku":"5131465","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/new-year-3-digit-addition-with-regrouping-worksheets-grade-3-5131465.jpg?v=1792460694"},{"product_id":"3-digit-subtraction-across-zeros-mystery-detective-worksheets-grades-2-6-winter-theme","title":"3-Digit Subtraction Across Zeros | Mystery Detective Worksheets | Grades 2–6 | Winter Theme","description":"\u003cp\u003e3 digit subtraction across zeros worksheets for 3rd grade and 4th grade, five winter Mystery Detective math cases on the regrouping students find hardest. Winter math for December, January and February, then no prep math centers, early finishers, homework and sub plans, print and go with full answer keys. Every correct answer crosses a suspect off the lineup and a wrong one matches nobody, so these subtraction pages send the student back to the zeros on their own, and a CSI Mini Mystery Detective gets a class through the coldest weeks of the year.\u003c\/p\u003e\n\n\u003cp\u003eSubtracting across zeros is usually one question buried in a mixed page, and a whole set of it is what a class needs the week the topic goes wrong. Ice skates, a snowman surprise and a lost pair of skis carry the CSI Mini Mystery Detective math cases, and the lineup catches the borrowed ten before you have to. Keep one case for the review week.\u003c\/p\u003e\n\u003cp\u003eThe zero sits in the tens place, so students have to borrow from the hundreds before they can subtract. The stories are about ice skates, a snowman that appeared overnight and skis that can't be found. Each answer matches one clue to cross off.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIce Skates\u003c\/strong\u003e - where the lost skates are\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSnowman Surprise\u003c\/strong\u003e - who built the snowman\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eClearing Snow\u003c\/strong\u003e - whose turn it is to shovel\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWhere are the Skis?\u003c\/strong\u003e - finding the missing skis\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWinter Sweater\u003c\/strong\u003e - who left a sweater behind\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFive winter cases\u003c\/li\u003e\n  \u003cli\u003e3 digit subtraction across zeros on every page\u003c\/li\u003e\n  \u003cli\u003eAn answer key for each case\u003c\/li\u003e\n  \u003cli\u003eTeacher instructions\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eEach case is one page with a winter story, subtraction problems and clue lists. Students cross off the clue that matches each answer, and the leftover clues solve it.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThese are for after subtracting across zeros has been taught, when students need practice on their own. 5th graders can use them as a refresher before decimal subtraction. Use them in math centers, small groups, as homework or on a sub day.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eWritten for 3rd grade and 4th grade.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eSubtracting across zeros on every page\u003c\/li\u003e\n  \u003cli\u003eA winter theme\u003c\/li\u003e\n  \u003cli\u003eNo prep\u003c\/li\u003e\n  \u003cli\u003eStudents catch a wrong borrow themselves\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWant more cases like these?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61955332505970,"sku":"7678309","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/3-digit-subtraction-across-zeros-worksheets-3rd-grade-7678309.jpg?v=1792462371"},{"product_id":"3-digit-addition-with-regrouping-mystery-detective-worksheets-grades-2-4-christmas-around-the-world","title":"3-Digit Addition with Regrouping | Mystery Detective Worksheets | Grades 2–4 | Christmas Around the World","description":"\u003cp\u003eChristmas Around the World 3 digit addition math worksheets for 2nd grade and 3rd grade: five Mystery Detective style math cases with regrouping on every page. December math activities, no prep, print and go with full answer keys, for math centers, early finishers, homework, morning work and sub plans. Santa has lost every label, and the story runs across all five pages, so a class comes back for the next one. It is 3 digit addition with regrouping practice for 2nd grade and 3rd grade that pairs with a Christmas Around the World unit, works as December math activities for math centers or morning work, and every CSI Mini Mystery Detective page is self-marking.\u003c\/p\u003e\n\n\u003cp\u003eOne story across five CSI Mini Mystery Detective math cases is why this set holds a class for a week rather than a lesson, and it pairs with a Christmas Around the World unit without any extra planning. Students add their way to each label, and the marking is student-led, with answer keys included.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChristmas Present One\u003c\/strong\u003e - Santa has lost every label\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChristmas Present Two\u003c\/strong\u003e - a second gift with no name\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChristmas Present Three\u003c\/strong\u003e - one more parcel nobody can claim\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChristmas Present Four\u003c\/strong\u003e - another gift Santa cannot deliver\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChristmas Present Five\u003c\/strong\u003e - the last parcel with no name\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eFive case files, each with a crime sheet and its own lineup of suspects\u003c\/li\u003e\n  \u003cli\u003eThree digit addition with regrouping on every page\u003c\/li\u003e\n  \u003cli\u003eOne running story across all five cases, with a present to deliver in each\u003c\/li\u003e\n  \u003cli\u003eEach answer matches one suspect and no other, so the page checks itself\u003c\/li\u003e\n  \u003cli\u003eA full answer key for every case\u003c\/li\u003e\n  \u003cli\u003ePrint and go: no cutting, no laminating, nothing to prepare\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mini Mystery Detective is one printed page carrying one crime and one lineup. Each suspect has a number, the crime sheet produces those numbers, and a correct answer removes that suspect until a single name is left. Nothing is laminated, charged or bought, so the math does the whole job, and that is the difference between these detective activities and a page of math worksheets. A case runs about a class period.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eDecember is the month, and the Christmas Around the World unit is the natural place for it, but what makes this one work is the story running through all five cases. Students finish one present and want the next, which is how you get five pages of carrying practice out of a class that has stopped listening. A dropped carry sends the wrong gift to the wrong person and they spot it.\u003c\/p\u003e\n\n\u003cp\u003eUse it for test prep, homework, math centers, morning work, early finishers, sub plans and homeschool lessons, with a whole class, a small group or one child alone.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWritten for 2nd grade and 3rd grade, where three digit addition with regrouping sits in the standards. Fourth graders take it as a December refresher, and second graders manage it once two digit carrying is secure.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eOne story across five cases, so students want the next page\u003c\/li\u003e\n  \u003cli\u003eStudents see a dropped carry when the wrong name comes off the lineup\u003c\/li\u003e\n  \u003cli\u003eNo prep in the last weeks of term\u003c\/li\u003e\n  \u003cli\u003eWorks with a whole class, a small group, partners, or one student alone\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61955440312690,"sku":"5070578","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/christmas-around-the-world-3-digit-addition-regrouping-grade-3-5070578.jpg?v=1792460694"},{"product_id":"rounding-to-the-nearest-10-and-100-mystery-detective-worksheets-grades-2-4-monster-theme","title":"Rounding to the Nearest 10 and 100 | Mystery Detective Worksheets | Grades 2–4 | Monster Theme","description":"\u003cp\u003eRounding to the nearest 10 and 100 worksheets for 3rd grade and 4th grade, six monster CSI Mini Mystery Detective math cases where every rounded number crosses a suspect off the lineup until one is left. Three cases round to the nearest 10 and three to the nearest 100, so these rounding math activities cover the whole standard and check themselves, because a number rounded the wrong way lands on no suspect. Print and go with full answer keys: no prep math centers, morning work, early finishers, homework and sub plans all year.\u003c\/p\u003e\n\n\u003cp\u003eSix CSI Mini Mystery Detective math cases is more than most rounding packs give you, which means a full week of practice plus one spare, with the nearest 10 and the nearest 100 kept on separate pages so you can teach one before the other. The monsters keep a third grader on the page, and the lineup tells them when to look again before you have to.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe Student Monster\u003c\/strong\u003e - something is loose in the school\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMonster Principal\u003c\/strong\u003e - the principal is not himself today\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMonster Teacher\u003c\/strong\u003e - extra schoolwork for everybody\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSchool Imposter Among Us\u003c\/strong\u003e - something got inside the school\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMonster Thief\u003c\/strong\u003e - every school book has gone\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe Teachers Lunch\u003c\/strong\u003e - the lunch disappears before noon\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eSix case files, each with a crime sheet and its own lineup of suspects\u003c\/li\u003e\n  \u003cli\u003eThree cases round to the nearest 10 and three round to the nearest 100\u003c\/li\u003e\n  \u003cli\u003eNumbers that sit either side of the halfway point, so the rule gets tested properly\u003c\/li\u003e\n  \u003cli\u003eEach answer matches one suspect and no other, so the page checks itself\u003c\/li\u003e\n  \u003cli\u003eA full answer key for every case\u003c\/li\u003e\n  \u003cli\u003ePrint and go: no cutting, no laminating, nothing to prepare\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mini Mystery Detective is a single page investigation your class solves with math. The lineup of suspects each carry a number, the crime sheet produces those numbers, and a correct answer removes one suspect until a single name is left holding it. There is no kit, no app and nothing to assemble, so the arithmetic does all the work, which is what makes detective activities stick where math worksheets slide off. One case runs about a class period.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eSix cases split across two scopes means you can teach rounding to the nearest 10 one day and the nearest 100 the next without handing out the same page twice. Use it through the rounding unit and again before testing, when students have started rounding to whatever place looks easiest. Rounding to the wrong place crosses off the wrong suspect, so the habit gets caught on the page.\u003c\/p\u003e\n\n\u003cp\u003eIt covers test prep, homework, math centers, morning work, early finishers, sub plans and homeschool lessons, with a whole class, a small group or one student alone.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWritten for 3rd grade, where rounding to the nearest 10 and 100 sits in the standards, and used with 4th graders as a warm up before rounding to larger places. Second graders take the nearest 10 cases once place value to 100 is secure.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eSix cases in one download, split so you can teach the two scopes apart\u003c\/li\u003e\n  \u003cli\u003eStudents catch their own rounding slips when the wrong suspect comes off\u003c\/li\u003e\n  \u003cli\u003eNo prep, and the answer keys make grading quick\u003c\/li\u003e\n  \u003cli\u003eWorks with a whole class, a small group, partners, or one student alone\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61955485237618,"sku":"9112300","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/rounding-to-the-nearest-10-and-100-worksheets-3rd-grade-9112300.jpg?v=1792461951"},{"product_id":"3-digit-subtraction-with-regrouping-mystery-detective-worksheets-grades-2-4-christmas-theme","title":"3-Digit Subtraction with Regrouping | Mystery Detective Worksheets | Grades 2–4 | Christmas Theme","description":"\u003cp\u003eChristmas 3 digit subtraction with regrouping worksheets for 2nd grade and 3rd grade: five printable math activities, Mystery Detective style, borrowing across the columns on every page. No prep, print and go, full answer keys, for morning work, math centers, early finishers, homework and sub plans through December. December is a good month for subtraction with regrouping practice, and this pack gives 2nd grade and 3rd grade students a week of it inside a school Christmas story. It works as Christmas math activities for math centers, morning work or the class party week, and a CSI Mini Mystery Detective marks itself.\u003c\/p\u003e\n\n\u003cp\u003eBorrowing fits the week of the class party perfectly when there is a reason to care, and an unsigned box of chocolates on the desk is that reason. The pages mark themselves as students cross the suspects off. It is math practice and a Mystery Detective case in one.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eClass Secret Santa\u003c\/strong\u003e - a gift with no label\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChristmas Chocolates\u003c\/strong\u003e - chocolates on the desk, unsigned\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChristmas Carols\u003c\/strong\u003e - singing from the music room\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChristmas Presents\u003c\/strong\u003e - who unwraps theirs first\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChristmas Good Deeds\u003c\/strong\u003e - kindness and nobody owning up\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eFive Christmas cases, each a page of 3 digit subtraction with regrouping\u003c\/li\u003e\n  \u003cli\u003eSixteen questions per case, laid out in columns ready to borrow\u003c\/li\u003e\n  \u003cli\u003eClue lists down the side of every page, so one answer removes one clue\u003c\/li\u003e\n  \u003cli\u003eA black and white copy of all five cases for everyday printing\u003c\/li\u003e\n  \u003cli\u003eAn answer key for every case\u003c\/li\u003e\n  \u003cli\u003ePrint and go: no cutting, no laminating, nothing to set up\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mini Mystery Detective is one page carrying a crime, a short list of clues and the questions that eliminate them. Every clue has a number, the subtraction produces those numbers, and a correct answer crosses that clue off until only the solution is left. Nothing is cut, laminated or charged. The borrowing has to be right for the elimination to work, which is what makes a mistake show.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eKeep this one for the fortnight before the break, when the timetable is broken up by rehearsals and parties and a lesson has to run on its own. It is also the set to use straight after the holidays, because borrowing across columns is the first thing a class forgets. Every instruction is printed on the sheet, so a relief teacher can hand it out with no briefing.\u003c\/p\u003e\n\n\u003cp\u003eUse it for morning work, math centers, early finishers, homework, class parties, sub plans and homeschool lessons, with a whole class, a small group or one student.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWritten for 2nd grade and 3rd grade. Second graders meet borrowing across columns here, and third graders use the cases as a December refresher before four digit subtraction.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eStudents keep going in the week nothing else holds them\u003c\/li\u003e\n  \u003cli\u003ePrint and hand out, with no preparation at all\u003c\/li\u003e\n  \u003cli\u003eFive cases carries the whole fortnight before the break\u003c\/li\u003e\n  \u003cli\u003eSuits a whole class, a small group, partners or one student\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61955548021106,"sku":"5027667","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/christmas-3-digit-subtraction-with-regrouping-worksheets-2nd-3rd-grade-5027667.jpg?v=1792460826"},{"product_id":"3-digit-addition-with-regrouping-mystery-detective-worksheets-grades-2-4-valentines-day","title":"3-Digit Addition with Regrouping | Mystery Detective Worksheets | Grades 2–4 | Valentine's Day","description":"\u003cp\u003eValentines Day 3 digit addition with regrouping math activities for 2nd grade and 3rd grade: five math sheets, each a Mystery Detective page. Print and go, no prep, full answer keys, for February math centers, morning work, early finishers, homework and sub plans. A dinner nobody will claim, a secret gift on the desk and flowers with not a word from anyone carry the week, a correct sum crosses a suspect off the lineup and a wrong one crosses off nobody, so the carrying across the tens and hundreds is real practice on every CSI Mini Mystery Detective page.\u003c\/p\u003e\n\n\u003cp\u003eThis one earns its place in February and then keeps working, because the addition is the point and the valentines are the setting. Students add their way to whoever left the flowers, the marking is student-led, and one CSI Mini Mystery Detective math case a day covers the week of the party with nothing to prepare.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eValentines Dinner Surprise\u003c\/strong\u003e - a dinner nobody will claim\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eValentines Gift\u003c\/strong\u003e - a secret gift on the desk\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eShowing Mindfulness\u003c\/strong\u003e - quiet good deeds around the school\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eValentines Day Card\u003c\/strong\u003e - a card with no signature\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eValentine Flowers\u003c\/strong\u003e - flowers and not a word from anyone\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eFive case files, each with a crime sheet and its own lineup of suspects\u003c\/li\u003e\n  \u003cli\u003eThree digit addition with regrouping on every page\u003c\/li\u003e\n  \u003cli\u003eCarrying across the tens and the hundreds on most problems\u003c\/li\u003e\n  \u003cli\u003eEach answer matches one suspect and no other, so the page checks itself\u003c\/li\u003e\n  \u003cli\u003eA full answer key for every case\u003c\/li\u003e\n  \u003cli\u003ePrint and go: no cutting, no laminating, nothing to prepare\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mini Mystery Detective is one printed page holding one crime and one lineup. Every suspect carries a number, the questions on the crime sheet produce those numbers, and a correct answer takes that suspect out until a single name is left. Nothing is cut, laminated or charged, so the arithmetic does all the work, and that is what separates these detective activities from ordinary math worksheets. A case fits one class period.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eFebruary needs math that survives a week of cards and candy, and this set does that while still being real three digit practice. Use it in the run up to Valentines Day and again in March, when carrying quietly starts to slip. Because a dropped carry puts the wrong name in the frame, students go back and check the column instead of assuming they were right.\u003c\/p\u003e\n\n\u003cp\u003eIt carries test prep, homework, math centers, morning work, early finishers, sub plans and homeschool lessons, with a class, a small group or one student alone.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWritten for 2nd grade and 3rd grade, where three digit addition with regrouping sits in the standards. Fourth graders take it as a February refresher, and second graders manage it once two digit carrying is secure.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eReal three digit carrying practice, with a February theme over it\u003c\/li\u003e\n  \u003cli\u003eStudents recheck their own columns when the wrong suspect goes\u003c\/li\u003e\n  \u003cli\u003eNo prep, and the answer keys make grading quick\u003c\/li\u003e\n  \u003cli\u003eWorks with a whole class, a small group, partners, or one student alone\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61955550740850,"sku":"5158427","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/valentines-day-3-digit-addition-with-regrouping-worksheets-5158427.jpg?v=1792460694"},{"product_id":"3-digit-subtraction-with-regrouping-mystery-detective-worksheets-grades-2-4-st-patricks-day","title":"3-Digit Subtraction with Regrouping | Mystery Detective Worksheets | Grades 2–4 | St. Patrick's Day","description":"\u003cp\u003e3 digit subtraction with regrouping St Patricks Day math worksheets for 2nd grade and 3rd grade, five Mystery Detective math cases for the March week. No prep math activities with full answer keys, print and go, for math centers, early finishers, homework, morning work and sub plans. Missing green balloons, an invitation with no sender and a shamrock left overnight carry the cases, the right answer clears a suspect and a wrong one lands on nobody, so the borrowing across the tens and hundreds checks itself on every CSI Mini Mystery Detective page.\u003c\/p\u003e\n\n\u003cp\u003eThe day before a St Patricks Day assembly is where these CSI Mini Mystery Detective math cases save you, because a class will subtract its way to the culprit without anyone at the front. Marking is student-led, with the answer keys there for a quick glance.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMissing Green Balloons\u003c\/strong\u003e - every green balloon disappears\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSt Patricks Invitation\u003c\/strong\u003e - an invitation with no sender\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eShamrock For Teacher\u003c\/strong\u003e - a shamrock left overnight\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLeprechaun Dress Up\u003c\/strong\u003e - one teacher is under the hat\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSt Patricks Kindness\u003c\/strong\u003e - somebody is doing good all day\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eFive case files, each with a crime sheet and its own lineup of suspects\u003c\/li\u003e\n  \u003cli\u003eThree digit subtraction with regrouping on every page\u003c\/li\u003e\n  \u003cli\u003eBorrowing across the tens and the hundreds, not just once per problem\u003c\/li\u003e\n  \u003cli\u003eEach answer matches one suspect and no other, so the page checks itself\u003c\/li\u003e\n  \u003cli\u003eA full answer key for every case\u003c\/li\u003e\n  \u003cli\u003ePrint and go: no cutting, no laminating, nothing to prepare\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mini Mystery Detective is a printable case with a lineup of suspects, each carrying a number. The questions on the crime sheet produce those numbers, a correct answer strikes one suspect off, and the last name standing is the culprit. The elimination only works when the math is right, which is what makes these detective activities show up mistakes a page of math worksheets would hide. One case fits one class period.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eMarch is the obvious month, and the day before a St Patricks Day assembly is the moment this saves you. Underneath the shamrocks it is straight three digit borrowing practice, which is the skill second and third graders lose fastest. Getting a borrow wrong puts the wrong name in the frame, so students check the column themselves and you are not the one finding every mistake.\u003c\/p\u003e\n\n\u003cp\u003eIt covers test prep, homework, math centers, morning work, early finishers, sub plans and homeschool lessons, with a class, a small group or one child alone.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWritten for 2nd grade and 3rd grade, where three digit subtraction with regrouping sits in the standards. Fourth graders take it as a March refresher, and second graders manage it once two digit borrowing is secure.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eReal borrowing practice under a seasonal cover\u003c\/li\u003e\n  \u003cli\u003eStudents find the wrong column themselves when the wrong suspect comes off\u003c\/li\u003e\n  \u003cli\u003eNo prep in a week full of assemblies and green hats\u003c\/li\u003e\n  \u003cli\u003eWorks with a whole class, a small group, partners, or one student alone\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61955556376946,"sku":"5295754","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/st-patricks-day-3-digit-subtraction-with-regrouping-worksheets-5295754.jpg?v=1792460826"},{"product_id":"3-digit-addition-subtraction-mystery-detective-worksheets-grades-2-4-thanksgiving-theme","title":"3-Digit Addition \u0026 Subtraction | Mystery Detective Worksheets | Grades 2–4 | Thanksgiving Theme","description":"\u003cp\u003eThanksgiving 3 digit addition and subtraction math activities for 2nd grade and 3rd grade: five math activities in the Mystery Detective format, with carrying and borrowing on the same page. Print and go with full answer keys, no prep, for morning work, math centers, early finishers, homework and sub plans in the week before the break. Thanksgiving math with regrouping for 2nd grade and 3rd grade, carrying and borrowing on the same page, all set around a school Thanksgiving. It suits November math centers, morning work and the days before the break, and it prints and goes as five CSI Mini Mystery Detective cases.\u003c\/p\u003e\n\n\u003cp\u003eSomebody has to carve the turkey and nobody will say who, which is enough to get a second grade class through a page of three digit regrouping in the week they are most excited about everything else. Each answer takes a clue off the list, so the pages are self-marking. One CSI Mini Mystery Detective math case a day covers the short week.\u003c\/p\u003e\n\u003cp\u003eThe first case asks who's going to carve the turkey, and the others follow a thank you gift, a surprise lunch for the teachers and a family trip. Students add and subtract with regrouping, then cross off the clue that matches each answer. When the work is right, one answer is left in each list.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWho is Carving the Turkey\u003c\/strong\u003e - the family feast needs a carver\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThankful Teacher\u003c\/strong\u003e - a student the teacher wants to thank\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThank You Gift\u003c\/strong\u003e - an unsigned gift on the desk\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSurprise Lunch\u003c\/strong\u003e - lunch made for the teachers\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eVacation Time\u003c\/strong\u003e - a student's family Thanksgiving trip\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFive Thanksgiving cases in color\u003c\/li\u003e\n  \u003cli\u003eBlack and white copies of all five\u003c\/li\u003e\n  \u003cli\u003eAn answer key for each case\u003c\/li\u003e\n  \u003cli\u003e3 digit addition and subtraction with regrouping\u003c\/li\u003e\n  \u003cli\u003eTeacher instructions\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA CSI Mini Mystery Detective is a one-page case. Students read the story, solve the problems and use each answer to cross off a clue. The clues that are still there at the end tell them what happened.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThis is for the weeks leading up to Thanksgiving. The math is plain 3 digit regrouping, though, so it also works as mixed addition and subtraction review at other times. Use a case as a bell ringer, with a small group, on a sub day or for homeschool.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eWritten for 2nd grade and 3rd grade, as practice at the end of the 3 digit unit or as review.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eA Thanksgiving theme on every case\u003c\/li\u003e\n  \u003cli\u003eAddition and subtraction in one pack\u003c\/li\u003e\n  \u003cli\u003eNo prep\u003c\/li\u003e\n  \u003cli\u003eColor and black and white\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWant more cases like these?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61955562996082,"sku":"4995137","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/thanksgiving-3-digit-addition-and-subtraction-worksheets-2nd-3rd-grade-4995137.jpg?v=1792462233"},{"product_id":"rounding-to-the-nearest-10-and-100-mystery-detective-worksheets-grades-2-4-christmas-theme","title":"Rounding to the Nearest 10 and 100 | Mystery Detective Worksheets | Grades 2–4 | Christmas Theme","description":"\u003cp\u003eChristmas rounding worksheets for 3rd grade and 4th grade: six December cases of rounding to the nearest 10 and 100, where each rounded number crosses a classmate, a person or a place off the clue list. Three cases round to the nearest 10 and three to the nearest 100, so the pack covers the whole standard, and a number rounded the wrong way matches no clue. Print and go with full answer keys: no prep math centers, morning work, early finishers, homework and sub plans, six Mystery Detective cases of math in one download.\u003c\/p\u003e\n\n\u003cp\u003eRounding is taught in a fortnight and then quietly forgotten, and the last weeks of December are exactly when it needs a run, because a stolen pile of presents and a gingerbread thief will get a third grade class through six pages of it. One case a day covers the fortnight before the break, and the answer keys keep the marking short. Every CSI Mini Mystery Detective math page checks itself.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMissing Xmas Presents\u003c\/strong\u003e - the school lot has gone\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWho Ate The Gingerbread\u003c\/strong\u003e - a classmate got there first\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSecret Santa\u003c\/strong\u003e - a gift and no name on it\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTeachers Xmas Present\u003c\/strong\u003e - a parcel nobody can explain\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChristmas Fruitcake\u003c\/strong\u003e - somebody baked for everyone\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWho Ate The Xmas Cookie\u003c\/strong\u003e - it happened again\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eSix Christmas cases, three on the nearest 10 and three on the nearest 100\u003c\/li\u003e\n  \u003cli\u003eA clue list beside the questions, so one answer removes one name\u003c\/li\u003e\n  \u003cli\u003eA red-ink answer key for all six cases\u003c\/li\u003e\n  \u003cli\u003eSix separate Christmas stories, so no two pages read the same\u003c\/li\u003e\n  \u003cli\u003eSized for one class period a case\u003c\/li\u003e\n  \u003cli\u003ePrint and go: no cutting, no laminating, nothing to prepare\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mini Mystery Detective is a printable case: one crime, one short clue list, and the questions that rule the clues out. Each clue carries a number, the rounding produces those numbers, and a match crosses that clue off until one name is left. Round to the wrong place and nothing matches, which is what makes the page mark itself.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eDecember is where this one belongs, in the fortnight before the break when a plain page of numbers will not hold a class. It also does a real job in the new year, because rounding is among the first things to go rusty over a holiday. The six cases split neatly into two sets of three, so you can hand out the nearest 10 group first and keep the nearest 100 group for the following week.\u003c\/p\u003e\n\n\u003cp\u003eUse it for morning work, math centers, early finishers, homework, test prep, sub plans and homeschool lessons, with a whole class, a small group or one student.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWritten for 3rd grade and 4th grade. Third graders meet rounding to 10 and 100 here, and fourth graders use the same six cases as a refresher before rounding to larger places.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eBoth rounding places covered in one download\u003c\/li\u003e\n  \u003cli\u003eNo preparation in the month that has none to spare\u003c\/li\u003e\n  \u003cli\u003eSix cases is more than a week of morning work\u003c\/li\u003e\n  \u003cli\u003eWorks with a whole class, a small group, partners or one student\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61955566305650,"sku":"8830695","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/christmas-rounding-to-the-nearest-10-and-100-worksheets-3rd-grade-8830695.jpg?v=1792461821"},{"product_id":"3-digit-subtraction-with-regrouping-mystery-detective-worksheets-grades-2-4-valentines-day","title":"3-Digit Subtraction with Regrouping | Mystery Detective Worksheets | Grades 2–4 | Valentine's Day","description":"\u003cp\u003e3 digit subtraction with regrouping Valentines Day math worksheets for 2nd grade and 3rd grade, five Mystery Detective style math cases for the February week. No prep math activities with full answer keys, print and go, for math centers, early finishers, homework, morning work and sub plans. A chocolate surprise with no note, a card on a friend's desk and a voice nobody can place carry the week, the right answer clears a suspect and a wrong one clears nobody, so the borrowing across the tens and hundreds checks itself on every CSI Mini Mystery Detective page.\u003c\/p\u003e\n\n\u003cp\u003eThe week of the class party is when a lesson has to hold itself together, and a CSI Mini Mystery Detective math case holds a second grade class better than a page of subtraction does. Students borrow, match the answer to a name and cross it off, so the marking is student-led and a substitute has nothing to explain.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChocolate Surprise\u003c\/strong\u003e - a box appears with no note\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFriends Valentines Card\u003c\/strong\u003e - a card lands on a friend's desk\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eActs of Kindness\u003c\/strong\u003e - good deeds with nobody taking credit\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSinging Love Songs\u003c\/strong\u003e - a voice nobody can place\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBouquet of Flowers\u003c\/strong\u003e - flowers with no card attached\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eFive case files, each with a crime sheet and its own lineup of suspects\u003c\/li\u003e\n  \u003cli\u003eThree digit subtraction with regrouping on every page\u003c\/li\u003e\n  \u003cli\u003eBorrowing across the tens and the hundreds, so it is genuine practice\u003c\/li\u003e\n  \u003cli\u003eEach answer matches one suspect and no other, so the page checks itself\u003c\/li\u003e\n  \u003cli\u003eA full answer key for every case\u003c\/li\u003e\n  \u003cli\u003ePrint and go: no cutting, no laminating, nothing to prepare\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mini Mystery Detective is a single page investigation solved with arithmetic. Each suspect in the lineup carries a number, the crime sheet produces those numbers, and a correct answer takes that suspect out until one name is left. No locks, no app, nothing to assemble, which is why these detective activities get used on days that would otherwise call for math worksheets. Each case fits a class period and works in a center or a sub folder.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe week of Valentines Day is where this earns its money, because you still have subtraction to cover and the class has cards on the brain. Underneath the theme it is straight three digit borrowing, the skill that slips faster than anything else at this level. The wrong difference names the wrong suspect, so students check the column rather than handing the page in and waiting to be told.\u003c\/p\u003e\n\n\u003cp\u003eIt suits test prep, homework, math centers, morning work, early finishers, sub plans and homeschool lessons, with a class, a small group or one student alone.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWritten for 2nd grade and 3rd grade, where three digit subtraction with regrouping sits in the standards. Fourth graders take it as a February refresher, and second graders manage it once two digit borrowing is secure.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eStraight borrowing practice with a seasonal cover on it\u003c\/li\u003e\n  \u003cli\u003eStudents check their own columns when the wrong suspect comes off\u003c\/li\u003e\n  \u003cli\u003eNo prep in a week with a party in it\u003c\/li\u003e\n  \u003cli\u003eWorks with a whole class, a small group, partners, or one student alone\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61955572466034,"sku":"5167917","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/valentines-day-3-digit-subtraction-with-regrouping-worksheets-5167917.jpg?v=1792460826"},{"product_id":"3-digit-addition-subtraction-mystery-detective-worksheets-grades-2-4-fall-theme","title":"3-Digit Addition \u0026 Subtraction | Mystery Detective Worksheets | Grades 2–4 | Fall Theme","description":"\u003cp\u003eFall math for September, October and November, including the weeks around Halloween and Thanksgiving. Three digit addition and subtraction with regrouping for 2nd grade and 3rd grade, across five CSI Mini Mystery Detective math case files: two addition cases, two subtraction, and one that mixes both. That covers 3 digit addition with regrouping and subtraction with regrouping as math worksheets and math activities in one no prep download, then spiral review, test prep, math centers, early finishers, homework, morning work and sub plans for the rest of the year. CSI math with full answer keys, and detective activities that need no prep. Each answer clears one suspect from the lineup until a single name is left.\u003c\/p\u003e\n\n\u003cp\u003eOctober and November are not easy weeks to hold a class, and this set does that work for you. Each case is a fall story with its own lineup of suspects, and the way through is three digit addition and subtraction with regrouping done carefully, because every answer takes one name off the list. Print the lot on Monday and your morning work is sorted for the week.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe Fall Leaves\u003c\/strong\u003e - a whole tree stripped in one night\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe Pumpkin Patch\u003c\/strong\u003e - every last pumpkin has gone\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe Scarecrows\u003c\/strong\u003e - the scarecrows walk off the field\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eScattered Leaves\u003c\/strong\u003e - leaves thrown all over the yard\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe Missing Corn Cobs\u003c\/strong\u003e - the corn maze is stripped bare\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eFive case files, each with a crime sheet and its own lineup of suspects\u003c\/li\u003e\n  \u003cli\u003eTwo addition cases, two subtraction cases, and one that mixes the two\u003c\/li\u003e\n  \u003cli\u003eThree digit numbers throughout, with regrouping needed on both operations\u003c\/li\u003e\n  \u003cli\u003eEach answer matches one suspect and no other, so the page checks itself\u003c\/li\u003e\n  \u003cli\u003eA full answer key for every case\u003c\/li\u003e\n  \u003cli\u003ePrint and go: no cutting, no laminating, nothing to prepare\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mini Mystery Detective is one printed page, one crime and one class period. Each suspect in the lineup is tagged with a number, the questions on the left produce those numbers, and a correct answer knocks a suspect out until the last one standing is the culprit. Nothing needs cutting, laminating or charging, which is why these detective activities get used on days when ordinary math worksheets would be handed out. It works as a lesson, in math centers, or left behind for a substitute.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eSeptember, October and November is the natural run for this set, and the Halloween and Thanksgiving weeks are where it earns its keep. Regrouping is the skill that fades the moment you stop practicing it, and this keeps it alive without another column of sums. A regrouping slip crosses off the wrong suspect, so students go back and find the column they got wrong instead of handing the page in and hoping.\u003c\/p\u003e\n\n\u003cp\u003eIt covers test prep, homework, math centers, morning work, early finishers, sub plans and homeschool lessons, with a whole class, a small group or one child working alone.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWritten for 2nd grade and 3rd grade, where three digit regrouping sits in the standards. Second graders take the addition cases first, third graders handle subtraction across zeros, and fourth graders use the mixed case as a quick check before moving to four digit numbers.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eAddition and subtraction sit on separate pages, so you can teach them apart\u003c\/li\u003e\n  \u003cli\u003eStudents find their own regrouping slips when the wrong suspect is crossed off\u003c\/li\u003e\n  \u003cli\u003eNo prep, and the answer keys make grading quick\u003c\/li\u003e\n  \u003cli\u003eWorks with a whole class, a small group, partners, or one student alone\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61955625124210,"sku":"10436612","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/fall-3-digit-addition-and-subtraction-with-regrouping-10436612.jpg?v=1792460557"},{"product_id":"3-digit-addition-with-regrouping-mystery-detective-worksheets-grades-2-4-easter-theme","title":"3-Digit Addition with Regrouping | Mystery Detective Worksheets | Grades 2–4 | Easter Theme","description":"\u003cp\u003eEaster math activities for 2nd grade and 3rd grade: five egg hunt CSI Mini Mystery Detective math cases of 3 digit addition with regrouping, where a correct sum crosses a suspect off the lineup and a wrong one crosses off nobody. Every page carries across the tens and the hundreds, so these addition worksheets are real practice under the Easter cover, self-checking with full answer keys. No prep, print and go, for the week before the break, then math centers, early finishers, homework, morning work and sub plans.\u003c\/p\u003e\n\n\u003cp\u003eThe week before the Easter break is the hardest week of spring to hold a class, and five CSI Mini Mystery Detective math cases with a missing egg at the center of each one do the holding for you. Students add, find the suspect with that total and cross the name off, so the room works through the page without you at the front. One case a day and the week is covered.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe Missing Easter Egg\u003c\/strong\u003e - one egg stolen before the hunt\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEaster Egg Basket\u003c\/strong\u003e - a basket appears with no name on it\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMissing Easter Egg Basket\u003c\/strong\u003e - the bunny's basket is stolen\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe Easter Bunny Carrot\u003c\/strong\u003e - half a carrot, no culprit\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEaster Eggs for Everyone\u003c\/strong\u003e - an egg on every single desk\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eFive case files, each with a crime sheet and its own lineup of suspects\u003c\/li\u003e\n  \u003cli\u003eThree digit addition with regrouping on every page\u003c\/li\u003e\n  \u003cli\u003eCarrying across the tens and the hundreds, so it is not a single step\u003c\/li\u003e\n  \u003cli\u003eEach answer matches one suspect and no other, so the page checks itself\u003c\/li\u003e\n  \u003cli\u003eA full answer key for every case\u003c\/li\u003e\n  \u003cli\u003ePrint and go: no cutting, no laminating, nothing to prepare\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mini Mystery Detective is a printable case with a lineup of suspects, each carrying a number. The questions on the crime sheet produce those numbers, a correct answer strikes one suspect off, and the last name standing is the culprit. The elimination only works when the math is right, which is what makes these detective activities show up mistakes a page of math worksheets would hide.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eMarch and April, and the days before the Easter break in particular, when carrying still needs practice and the class is already on holiday in their heads. Five short cases cover that stretch, and they are the right thing to leave for a substitute on the day before a long weekend. A dropped carry names the wrong suspect, so students find the column themselves.\u003c\/p\u003e\n\n\u003cp\u003eUse it for test prep, homework, math centers, morning work, early finishers, sub plans and homeschool lessons, with a whole class, a small group or one child alone.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWritten for 2nd grade and 3rd grade, where three digit addition with regrouping sits in the standards. Fourth graders take it as a spring refresher, and second graders manage it once two digit carrying is secure.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eFive short cases, enough for the whole week before the break\u003c\/li\u003e\n  \u003cli\u003eStudents find their own dropped carries when the wrong name goes\u003c\/li\u003e\n  \u003cli\u003eNo prep on the days nobody can concentrate\u003c\/li\u003e\n  \u003cli\u003eWorks with a whole class, a small group, partners, or one student alone\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61955688595826,"sku":"9343317","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/easter-3-digit-addition-with-regrouping-worksheets-csi-mystery-9343317.jpg?v=1792460694"},{"product_id":"3-digit-addition-with-regrouping-mystery-detective-worksheets-grades-2-4-halloween-zombie-theme","title":"3-Digit Addition with Regrouping | Mystery Detective Worksheets | Grades 2–4 | Halloween Zombie Theme","description":"\u003cp\u003eHalloween zombie math worksheets for 2nd grade and 3rd grade: five Mystery Detective style math cases on 3 digit addition with regrouping. Print and go with full answer keys, no prep, for October math centers, early finishers, homework and sub plans. Zombies take over the school, a classmate is not human, a friend needs saving and a leader needs finding, with carrying across the tens and hundreds on every page; the right sum clears a suspect and the wrong one clears nobody, which is why a class stays on a CSI Mini Mystery Detective to the last sum.\u003c\/p\u003e\n\n\u003cp\u003eOctober is when this one earns its keep, the two weeks before Halloween most of all, and a zombie leader to find is why a class works five CSI Mini Mystery Detective math cases of addition with real enthusiasm. Each total points at one suspect, so students check their carrying before they cross anyone off, and the answer keys make the marking quick. Pair it with the zombie subtraction pack.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eZombies Take Over\u003c\/strong\u003e - find somewhere safe to hide\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eZombie Classmate\u003c\/strong\u003e - one classmate is not human\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSave your friend\u003c\/strong\u003e - a friend is lost in the chase\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eZombie Leader\u003c\/strong\u003e - find who is giving the orders\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eZombie Teacher\u003c\/strong\u003e - find the cure before the bell\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eFive case files, each with a crime sheet and its own lineup of suspects\u003c\/li\u003e\n  \u003cli\u003eThree digit addition with regrouping on every page\u003c\/li\u003e\n  \u003cli\u003eCarrying needed in more than one column, so it is real regrouping practice\u003c\/li\u003e\n  \u003cli\u003eEach answer matches one suspect and no other, so the page checks itself\u003c\/li\u003e\n  \u003cli\u003eA full answer key for every case\u003c\/li\u003e\n  \u003cli\u003ePrint and go: no cutting, no laminating, nothing to prepare\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mini Mystery Detective gives your class a crime, a lineup and a page of questions, and the only route to the culprit runs through the math. Each suspect wears a number, each correct answer matches one of them, and that name is struck off until a single suspect is left. Because a wrong sum rules out the wrong person, these detective activities push students to check their work in a way math worksheets do not. One case fills a class period.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eOctober is when most teachers pull this out, but the five cases run as a story, which makes it just as useful as a week of morning work whenever three digit addition needs keeping alive. Boys who will not touch a worksheet will finish a zombie case, and that is most of the battle. A missed carry names the wrong suspect, so students check their own columns before they hand anything in.\u003c\/p\u003e\n\n\u003cp\u003eUse it for test prep, homework, math centers, morning work, early finishers, sub plans and homeschool lessons, with a whole class, a small group or one child alone.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWritten for 2nd grade and 3rd grade, where three digit addition with regrouping sits in the standards. Fourth graders take it as an October warm up, and second graders manage it once two digit carrying is secure.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eA story that runs across five cases, so students want the next page\u003c\/li\u003e\n  \u003cli\u003eStudents find a missed carry themselves when the wrong name comes off\u003c\/li\u003e\n  \u003cli\u003eNo prep, and the answer keys make grading quick\u003c\/li\u003e\n  \u003cli\u003eWorks with a whole class, a small group, partners, or one student alone\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61955719070066,"sku":"6650210","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/halloween-3-digit-addition-with-regrouping-worksheets-2nd-3rd-grade-6650210.jpg?v=1792460694"},{"product_id":"3-digit-subtraction-with-regrouping-mystery-detective-worksheets-grades-2-4-halloween-zombie-theme","title":"3-Digit Subtraction with Regrouping | Mystery Detective Worksheets | Grades 2–4 | Halloween Zombie Theme","description":"\u003cp\u003eZombie 3 digit subtraction with regrouping worksheets for 2nd grade and 3rd grade, five Halloween math case files, Mystery Detective style. October math activities for the two weeks before Halloween, then no prep math centers, early finishers, homework, morning work and sub plans, print and go with full answer keys. Find the zombie, the classmate, the principal and the lair by borrowing across the tens and hundreds on every page, where each answer crosses a suspect off the lineup and a wrong one crosses off nobody, so a CSI Mini Mystery Detective marks itself.\u003c\/p\u003e\n\n\u003cp\u003eStudents will happily work through five pages of subtraction to find a zombie, and that is the whole reason this set exists. The story runs across the CSI Mini Mystery Detective math cases so they come back for the next one, and the lineup catches a borrowed ten gone wrong before you do. Pair it with the zombie addition pack for a full Halloween week.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFind the Zombie\u003c\/strong\u003e - one is hiding in the school\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eZombie Classmate\u003c\/strong\u003e - one classmate is not human\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eZombie Principal\u003c\/strong\u003e - the principal has turned\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eZombie Attack\u003c\/strong\u003e - the whole school is turning\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eZombie Lair\u003c\/strong\u003e - a hidden lair in the building\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eFive case files, each with a crime sheet and its own lineup of suspects\u003c\/li\u003e\n  \u003cli\u003eThree digit subtraction with regrouping on every page\u003c\/li\u003e\n  \u003cli\u003eBorrowing needed across the tens and the hundreds\u003c\/li\u003e\n  \u003cli\u003eEach answer matches one suspect and no other, so the page checks itself\u003c\/li\u003e\n  \u003cli\u003eA full answer key for every case\u003c\/li\u003e\n  \u003cli\u003ePrint and go: no cutting, no laminating, nothing to prepare\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mini Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mini Mystery Detective is one page, one crime and one class period. The suspects stand in a lineup with a number each, the questions on the crime sheet produce those numbers, and a correct answer knocks a suspect out until the last name standing is the culprit. There is nothing to cut or set up, so the arithmetic carries the whole thing, which is what separates detective activities from ordinary math worksheets.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eOctober is the month, but the real reason to use this is that borrowing twice in a sum needs far more practice than a unit usually allows, and five zombie cases will get that practice done. The story pulls students through page after page of the skill they would otherwise stall on. A wrong borrow crosses off the wrong suspect, so the mistake is caught before it becomes a habit across the whole sheet.\u003c\/p\u003e\n\n\u003cp\u003eIt covers test prep, homework, math centers, morning work, early finishers, sub plans and homeschool lessons, with a class, a small group or one student alone.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWritten for 2nd grade and 3rd grade, where three digit subtraction with regrouping sits in the standards. Fourth graders take it as an October refresher, and second graders manage it once two digit borrowing is secure.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love These Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eBorrowing across two columns, which is the part that needs the repetitions\u003c\/li\u003e\n  \u003cli\u003eStudents catch a wrong borrow when the wrong suspect comes off\u003c\/li\u003e\n  \u003cli\u003eNo prep, and the answer keys make grading quick\u003c\/li\u003e\n  \u003cli\u003eWorks with a whole class, a small group, partners, or one student alone\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61955727524210,"sku":"6664744","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/halloween-3-digit-subtraction-with-regrouping-worksheets-2nd-3rd-grade-6664744.jpg?v=1792460826"},{"product_id":"addition-subtraction-within-1000-digital-escape-room-math-activity-grades-2-4-st-patricks-day","title":"Addition \u0026 Subtraction Within 1000 Digital Escape Room | Math Activity | Grades 2–4 | St Patrick's Day","description":"\u003cp\u003e\u003cstrong\u003eRegroup your way past the leprechaun's locks\u003c\/strong\u003e — this Addition \u0026amp; Subtraction Within 1000 Digital Escape Room sends students through a St Patrick's Day adventure, working with three-digit numbers to crack each code and escape.\u003c\/p\u003e\u003cp\u003eIt's fully digital and self-checking, so wrong answers won't open the lock and there's nothing for you to grade. Built for Grades 2–4 with a St Patrick's Day theme. Open it in any browser — no app, login, or subscription.\u003c\/p\u003e\u003ch3\u003eQuick details\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eGrade levels:\u003c\/strong\u003e 2–4 (addition and subtraction within 1000)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFormat:\u003c\/strong\u003e Interactive, browser-based digital escape room\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eResource type:\u003c\/strong\u003e No-prep, self-checking math activity\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSkill focus:\u003c\/strong\u003e Addition and subtraction within 1000\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTech needed:\u003c\/strong\u003e Any device with a web browser\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eThe mission\u003c\/h3\u003e\u003cp\u003eThe pot of gold is locked behind a string of three-digit problems. Students add and subtract within 1000 — solve correctly and the codes appear, one puzzle at a time.\u003c\/p\u003e\u003ch3\u003eHow the escape room works\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eOpen the private link in any browser — no app, login, or subscription\u003c\/li\u003e\n\u003cli\u003eSolve each addition or subtraction problem to reveal a code\u003c\/li\u003e\n\u003cli\u003eEnter the code to unlock the next stage — wrong answers won't open it\u003c\/li\u003e\n\u003cli\u003eThe room self-checks, so students get instant feedback\u003c\/li\u003e\n\u003cli\u003eCrack the final code to escape\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eWhat's included\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eAn interactive digital escape room hosted on a private site\u003c\/li\u003e\n\u003cli\u003eAnimated, self-checking puzzles with randomized answers for replayability\u003c\/li\u003e\n\u003cli\u003eNo Boom Cards, Google Slides, logins, or subscriptions\u003c\/li\u003e\n\u003cli\u003eA PDF with your private access link to share via Google Classroom, email, or your LMS\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eSkills covered\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eAdding within 1000\u003c\/li\u003e\n\u003cli\u003eSubtracting within 1000\u003c\/li\u003e\n\u003cli\u003eRegrouping across place values\u003c\/li\u003e\n\u003cli\u003eSolving multi-step word problems\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eBest used for\u003c\/h3\u003e\u003cp\u003eMath centers, tech time, early finishers, sub plans, St Patrick's Day and March review, homeschool, and distance learning.\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61958589874546,"sku":"13149256","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/st-patricks-day-addition-subtraction-within-1000-digital-escape-room-1.jpg?v=1781990244"},{"product_id":"rounding-to-the-nearest-10-and-100-digital-escape-room-math-activity-grades-3-5","title":"Rounding to the Nearest 10 and 100 Digital Escape Room | Math Activity | Grades 3-5","description":"\u003cp\u003e\u003cstrong\u003eLock the lesson and hand over a link.\u003c\/strong\u003e Your students step into an interactive escape room where every locked door hides a rounding challenge. Solve it, reveal the code, and work your way out before time runs out.\u003c\/p\u003e\n\u003cp\u003eIt's a no-prep, self-checking review game that runs in any browser — no apps, no logins, no printing. Just send the link and let them race the clock.\u003c\/p\u003e\n\u003ch3\u003eQuick details\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eGrade levels:\u003c\/strong\u003e 3-5\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFormat:\u003c\/strong\u003e Interactive, browser-based digital escape room\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eResource type:\u003c\/strong\u003e No-prep, self-checking review game\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSkill focus:\u003c\/strong\u003e Rounding to the nearest 10 and 100\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTech needed:\u003c\/strong\u003e Any device with a web browser\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eThe mission\u003c\/h3\u003e\n\u003cp\u003eThe safe's combination is hidden in a string of rounded numbers. Round each one to the nearest 10 and 100, reveal the codes, and escape the room before time is up.\u003c\/p\u003e\n\u003ch3\u003eHow the escape room works\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eOpen the private link — no app or login required.\u003c\/li\u003e\n\u003cli\u003eWork through a series of animated rounding challenges.\u003c\/li\u003e\n\u003cli\u003eEach correct answer reveals a code that unlocks the next room.\u003c\/li\u003e\n\u003cli\u003eWrong answers won't open the lock, so the room checks itself.\u003c\/li\u003e\n\u003cli\u003eCrack the final code to escape and win.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWhat's included\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eAn interactive escape room hosted on a private site — animated, with randomized answers for replayability.\u003c\/li\u003e\n\u003cli\u003eNo Boom Cards, Google Slides, logins, or subscriptions.\u003c\/li\u003e\n\u003cli\u003eA PDF containing your private access link to share via Google Classroom, email, or any LMS.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSkills covered\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eRounding numbers to the nearest 10\u003c\/li\u003e\n\u003cli\u003eRounding numbers to the nearest 100\u003c\/li\u003e\n\u003cli\u003eUsing place value to round accurately\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eBest used for\u003c\/h3\u003e\n\u003cp\u003eMath centers, tech time, early finishers, sub plans, homeschool, test prep, review days, and distance learning.\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61959829881202,"sku":"12059790","price":3.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/rounding-to-10-and-100-digital-escape-room-1.jpg?v=1782006855"},{"product_id":"addition-subtraction-csi-mystery-worksheets-grades-3-6-the-secret-number","title":"Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 3–6 | The Secret Number","description":"\u003cp\u003eOctober CSI math worksheets for addition and subtraction review, even and odd numbers, and multiples on a hundreds chart, run as a CSI Mystery Detective case for 3rd grade, 4th grade and 5th grade. It covers the ground a class needs before a test or at the end of a unit, as a number investigation rather than a drill. Each correct answer eliminates a suspect, and the last name standing is the culprit, so the mystery only closes when every sum is right. Students regroup, sort even from odd up to 100, shade multiples of 3, and work a clue backwards to check it holds. Answer keys and black-and-white pages included.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA number is hiding, and every clue narrows down what it can be. Your students shade a hundreds chart, sort the odds from the evens, and work each answer against the evidence until only one number survives.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eAddition and subtraction with regrouping\u003c\/li\u003e\n  \u003cli\u003eTelling even numbers from odd numbers up to 100\u003c\/li\u003e\n  \u003cli\u003eFinding multiples of 3 on a hundreds chart and shading the pattern\u003c\/li\u003e\n  \u003cli\u003eWorking a clue backwards from the answer to check it holds\u003c\/li\u003e\n  \u003cli\u003eReading a chart and matching your answers against it\u003c\/li\u003e\n  \u003cli\u003eAnswer keys included\u003c\/li\u003e\n  \u003cli\u003eColor and black-and-white versions, so it prints clean on any copier\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mystery Detective case is math practice with a culprit at the end of it. The class works the page, each correct answer rules one out, and the case closes on the last one left. It runs like a math escape room with the hardware removed - no locks, no app, no prep. It is far harder to coast through than ordinary math worksheets, because the arithmetic has to hold or nothing lines up. Use it as a full math activity, in math centers, or as detective activities for early finishers.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eMath review before a test or at the end of a unit\u003c\/li\u003e\n  \u003cli\u003eMath centers and small groups\u003c\/li\u003e\n  \u003cli\u003eSub plans and emergency cover\u003c\/li\u003e\n  \u003cli\u003eEarly finishers and morning work\u003c\/li\u003e\n  \u003cli\u003eHomework that does not need explaining twice\u003c\/li\u003e\n  \u003cli\u003eThe last lesson of the week, when nothing else lands\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eDesigned for 3rd grade, 4th grade and 5th grade. A confident 2nd grader can handle the even and odd pages, and a 5th grader who still trips on regrouping gets honest practice rather than busywork.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love CSI Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eNo prep at all - print it and hand it out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking, so you are not hunting through thirty pages for one slipped digit\u003c\/li\u003e\n  \u003cli\u003eEvery clue uses a different puzzle shape, so the pack holds attention to the last page\u003c\/li\u003e\n  \u003cli\u003eStudents go back and check their own working, because they want to name the answer\u003c\/li\u003e\n  \u003cli\u003eQuiet, focused engagement without a single instruction repeated\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education to discover more CSI Mystery Detective cases, no-prep math review, and detective-themed printables for elementary classrooms.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61980734390642,"sku":"2671501","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/addition-and-subtraction-math-worksheets-detective-case-cover-54-2671501.jpg?v=1792459386"},{"product_id":"addition-subtraction-csi-mystery-worksheets-grades-2-5-the-valentines-surprise-card","title":"Addition \u0026 Subtraction CSI Mystery Worksheets | Grades 2–5 | The Valentine's Surprise Card","description":"\u003cp\u003eValentines Day CSI math worksheets for February, built around addition and subtraction with two-digit, three-digit and four-digit numbers and wrapped in a CSI Mystery Detective case. Someone left an unsigned envelope in a desk before the bell, and 2nd grade and 3rd grade students find out who by getting the math right. It is a fun subtraction and addition activity that doubles as solid practice, and the mystery keeps them working long after a plain page would have lost them. Zero setup - print and hand it over. Correct answers get colored, a cryptogram gets cracked, and a chain of linked clues narrows the line-up one suspect at a time. Answer keys included.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case: The Surprise Card\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eValentines Day is finally here and you have worn your best clothes to school for it. The bell goes, you open your desk for your math book, and there is an envelope sitting on top of it that you did not put there. No name on it. Somebody in this room got up early, and your students are going to work out which one.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eDeciding which number problems are correct and coloring the right answers\u003c\/li\u003e\n  \u003cli\u003eA cryptogram that reveals the color of a strand of hair left in the envelope\u003c\/li\u003e\n  \u003cli\u003eMulti-step problems where the last answers give a shoe size\u003c\/li\u003e\n  \u003cli\u003eChecking worked answers for errors and tallying which are correct\u003c\/li\u003e\n  \u003cli\u003eA sequence of linked clues that builds to one final number\u003c\/li\u003e\n  \u003cli\u003eFull color and black-and-white versions of every page\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for the whole case\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mystery Detective case is a printable math activity dressed as police work. Your class gets a crime, a line-up of suspects and a page of math worksheets, and the answers do the eliminating until one name is left. It is a math escape room without the locks, the app or the prep. Unlike a practice page it will not let a wrong answer pass quietly - the case stops closing - so students check as they go. Use it for a lesson, in math centers, or as detective activities for early finishers.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eValentines Day in February, when a normal worksheet will not hold them\u003c\/li\u003e\n  \u003cli\u003eAddition and subtraction review before or after a unit test\u003c\/li\u003e\n  \u003cli\u003eMath centers, early finishers and independent work\u003c\/li\u003e\n  \u003cli\u003eEmergency sub plans that run themselves\u003c\/li\u003e\n  \u003cli\u003eEnd of year review, when attention is thin and the work still has to happen\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBuilt for 2nd grade and 3rd grade. Second graders usually pair up on the larger numbers; third graders run the case independently. It also suits 4th grade students who need addition and subtraction review in a form that does not look like going back a year.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love CSI Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eZero prep - print and hand out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking by design, because a wrong answer breaks the deduction\u003c\/li\u003e\n  \u003cli\u003eA Valentines activity that still does real math\u003c\/li\u003e\n  \u003cli\u003eWorks as a whole lesson, a center, or a filler for an awkward afternoon\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education for new detective cases, seasonal math activities and updates on discounts and new releases.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61981846864242,"sku":"3607787","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/valentines-day-surprise-card-mystery-detective-add-subtract-grades-2-4-3607787.jpg?v=1792459172"},{"product_id":"christmas-addition-subtraction-csi-mystery-grades-2-5-secret-santa","title":"Christmas Addition \u0026 Subtraction CSI Mystery | Grades 2–5 | Secret Santa","description":"\u003cp\u003eDecember Christmas CSI math worksheets on addition and subtraction, wrapped around a Secret Santa mystery the class will want solved. One gift out of the hat was not what it should have been, and nobody will own up. Made for 2nd grade and 3rd grade, this CSI Mystery Detective case works two-digit and three-digit addition and subtraction, and each correct answer strikes one suspect from the list until only the guilty gift-giver is left. Christmas math activities that need nothing but a printer, in color or black-and-white, with answer keys. Students decode a map key, follow an addition path where odd or even settles the clue, and work subtraction through a letter key.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Case: Secret Santa\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThat time of year has come round again. Everyone has a bit of a skip in their step, a smile for strangers, an extra hug for relatives they see once a decade. Even Mrs McPuffers has gone soft. The Secret Santa names went into the hat, the gifts came out, and one of them was not what it should have been. Nobody will own up, so your students will have to work out who it was.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eReading letters off a map with a key to decode the first clue\u003c\/li\u003e\n  \u003cli\u003eAddition along a path where an odd or even final total decides the answer\u003c\/li\u003e\n  \u003cli\u003eAddition problems used to color the correct arrow forward\u003c\/li\u003e\n  \u003cli\u003eThree-digit addition decoded through a letter key\u003c\/li\u003e\n  \u003cli\u003eSubtraction worked through a key to reveal the final clue\u003c\/li\u003e\n  \u003cli\u003eFull color and black-and-white versions of every page\u003c\/li\u003e\n  \u003cli\u003eAnswer keys for the whole case\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective Case?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe format never changes: a crime, a line-up of suspects, and math that decides which of them it cannot be. A CSI Mystery Detective case is a math escape room that needs a printer instead of locks, an app or any setup. It beats a stack of math worksheets on the same content for one reason - a wrong answer breaks the deduction loudly, so students go back over their own work. It fills a whole lesson, sits in math centers, or works as detective activities for early finishers.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eThe last weeks of December, when a normal worksheet will not hold them\u003c\/li\u003e\n  \u003cli\u003eClass Secret Santa week, alongside the real thing\u003c\/li\u003e\n  \u003cli\u003eMath centers, early finishers and independent work\u003c\/li\u003e\n  \u003cli\u003eEmergency sub plans that run themselves\u003c\/li\u003e\n  \u003cli\u003eWhole-class detective sessions, small groups or partner work\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBuilt for 2nd grade and 3rd grade. Second graders usually work the three-digit pages in pairs; third graders run the case independently inside a lesson. It also suits 4th grade students who need addition and subtraction review in a form that does not feel like going backwards.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy Teachers Love CSI Mystery Detective Cases\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eZero prep - print and hand out\u003c\/li\u003e\n  \u003cli\u003eSelf-checking by design, because a wrong answer breaks the deduction\u003c\/li\u003e\n  \u003cli\u003eA December activity that still does real math\u003c\/li\u003e\n  \u003cli\u003eWorks as a whole lesson, a center, or a filler for an awkward afternoon\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLove this resource?\u003c\/p\u003e\n\n\u003cp\u003eFollow Kiwiland Education for new detective cases, seasonal math activities and updates on discounts and new releases.\u003c\/p\u003e\n\n\u003cp\u003e\u003ca href=\"https:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\" target=\"_blank\" rel=\"noopener\"\u003eFollow Kiwiland Education on TPT ↗\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61981869113714,"sku":"4216910","price":4.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/christmas-secret-santa-csi-mystery-detective-grades-2-5-4216910.jpg?v=1792459386"}],"url":"https:\/\/kiwilandeducation.com\/collections\/math-3-nbt.oembed","provider":"Kiwiland Education","version":"1.0","type":"link"}