{"title":"Grade 1 Math: Operations \u0026 Algebraic Thinking","description":"\u003cp\u003e1st grade math worksheets and activities for operations \u0026amp; algebraic thinking (Common Core 1.OA): printable mystery worksheets, CSI cases and digital escape rooms.\u003c\/p\u003e","products":[{"product_id":"adding-near-doubles-digital-escape-room-math-fact-fluency-activity-grades-1-2-valentines-day","title":"Adding Near Doubles Digital Escape Room | Math Fact Fluency Activity | Grades 1–2 | Valentine's Day","description":"\u003cp\u003e\u003cstrong\u003eDouble it, adjust by one, unlock the next clue\u003c\/strong\u003e — this Adding Near Doubles Digital Escape Room sends early learners through a Valentine's Day adventure, using doubles facts to solve near-doubles and crack each code to 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 1–2 with a Valentine'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 1–2 (near doubles \/ addition fact fluency)\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 Adding near doubles\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 Valentine's party is locked, and only quick thinking with doubles will open it. Students use known doubles to solve near-doubles facts — answer 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 near-doubles fact 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\u003eRecalling doubles facts\u003c\/li\u003e\n\u003cli\u003eUsing doubles to solve near doubles\u003c\/li\u003e\n\u003cli\u003eBuilding addition fact fluency\u003c\/li\u003e\n\u003cli\u003eMental math strategies\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eBest used for\u003c\/h3\u003e\u003cp\u003eMath centers, tech time, early finishers, sub plans, Valentine's Day and February review, homeschool, and distance learning.\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61958401786226,"sku":"10930479","price":3.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/valentines-day-adding-near-doubles-digital-escape-room-1.jpg?v=1781989388"},{"product_id":"addition-within-20-winter-digital-escape-room-math-activity-grades-k-2","title":"Addition Within 20 Winter Digital Escape Room | Math Activity | Grades K–2","description":"\u003cp\u003e\u003cstrong\u003eLock the lesson and hand over a link.\u003c\/strong\u003e Your students step into a snowed-in winter world where every frozen lock is really an addition-within-20 problem in disguise. Solve it, reveal the code, and melt your way to the exit.\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 watch 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 K–2\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 Addition within 20\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\u003eA snowstorm has frozen the cabin doors shut. The only way out is to solve a trail of winter addition puzzles, collect each code, and unlock the final door before the blizzard sets in.\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 addition 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\u003eAdding two numbers with sums to 20\u003c\/li\u003e\n\u003cli\u003eMental math fluency and number bonds\u003c\/li\u003e\n\u003cli\u003eProblem solving under a fun, themed challenge\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, review days, and distance learning.\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61959766573426,"sku":"10793305","price":3.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/winter-addition-within-20-digital-escape-room-1.jpg?v=1781999773"},{"product_id":"subtraction-within-20-winter-digital-escape-room-math-activity-grades-k-2","title":"Subtraction Within 20 Winter Digital Escape Room | Math Activity | Grades K–2","description":"\u003cp\u003e\u003cstrong\u003eLock the lesson and hand over a link.\u003c\/strong\u003e Your students step into a snowed-in winter world where every frozen lock is really a subtraction-within-20 problem in disguise. Solve it, reveal the code, and melt your way to the exit.\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 watch 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 K–2\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 Subtraction within 20\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\u003eA snowstorm has frozen the cabin doors shut. The only way out is to solve a trail of winter subtraction puzzles, collect each code, and unlock the final door before the blizzard sets in.\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 subtraction 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\u003eSubtracting within 20\u003c\/li\u003e\n\u003cli\u003eMental math fluency and number bonds\u003c\/li\u003e\n\u003cli\u003eProblem solving under a fun, themed challenge\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, review days, and distance learning.\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":61959770931570,"sku":"10793028","price":3.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/winter-subtraction-within-20-digital-escape-room-1.jpg?v=1782000990"},{"product_id":"addition-and-subtraction-within-20-mystery-detective","title":"Addition and Subtraction Within 20 | Mystery Detective | Grades 1–2 | Halloween","description":"\u003cp\u003e1st grade addition and subtraction within 20, written to 1.OA.C.6. Students add and subtract on the question cards, then use each answer to strike a suspect off the sheet until one name is left, which gives you math worksheets and math activities from one no prep download. A Halloween CSI Mystery Detective math case run as SCOOT task cards around the room, with Halloween math for October, then math centers, early finishers, homework, morning work, sub plans, test prep and review for the rest of the year. CSI math in color and black and white versions, with a full answer key and detective activities that need no prep.\u003c\/p\u003e\n\n\u003cp\u003e\u003c!--LEAD--\u003eFirst graders will do far more addition and subtraction on their feet than they will sitting down, and this is the resource that takes advantage of it. The cards go around the room, each answer takes a suspect off their sheet, and finding the culprit is the reward. Short enough that the whole class finishes together, and it is ready for early finishers any time after that.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eGhostly Giggles\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eSomething is laughing in the dark and the class is out to find it. Students move around the room card by card, and every answer they work out crosses another suspect off the sheet they are carrying. By the time the last card is done, only one name is left.\u003c\/p\u003e\n\n\n\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eEleven numbered question cards, written to 1.OA.C.6\u003c\/li\u003e\n  \u003cli\u003eAddition and subtraction within 20 on every card\u003c\/li\u003e\n  \u003cli\u003eA suspect sheet each student fills in as they move around the room\u003c\/li\u003e\n  \u003cli\u003eA color set and a black and white set of the same cards\u003c\/li\u003e\n  \u003cli\u003eThe answer key, with the culprit named\u003c\/li\u003e\n  \u003cli\u003ePrint, cut the cards once, and it is ready every year after that\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\n\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mystery Detective gives your class a crime, a lineup of suspects and a set of questions, and the only route to the culprit is the math. Each suspect wears a number, each correct answer matches one of them, and that name is crossed off until one has not been ruled out. Run as SCOOT the questions go on the wall and students travel between them, which is what separates these detective activities from ordinary math worksheets. One case fills a class period with no prep.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to Use This Resource\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eUse this in the last week of October, when nobody is sitting still and you still have facts within 20 on the plan. It gets first graders moving between cards instead of grinding down a worksheet, and the number of problems is small enough that the whole class finishes in one session. Each answer strikes a name off their own sheet, so a wrong sum shows itself before you ever look at 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 child working alone.\u003c\/p\u003e\n\n\n\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWritten for 1st grade, where 1.OA.C.6 sits. Kindergarten classes take it late in the year once addition within 10 is secure, and second graders use it as a start of year warm up before moving to within 100.\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\u003eEleven short questions, which is the right length for a first grade attention span\u003c\/li\u003e\n  \u003cli\u003eStudents check themselves as the suspects come off the sheet\u003c\/li\u003e\n  \u003cli\u003eOne cut and the cards are ready for every October after this one\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\n\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\"\u003ehttps:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":62593085407602,"sku":"10279129","price":4.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/first-grade-fact-fluency-1-oa-c-6-detective-game.jpg?v=1792612678"},{"product_id":"addition-and-subtraction-within-20-mystery-detective-mischievous-magician","title":"Addition and Subtraction Within 20 | Mystery Detective | Grades 1–2","description":"\u003cp\u003eA sub folder, a math center and an early finisher task in one file: a CSI Mystery Detective math case that runs as SCOOT task cards around the room, on addition and subtraction within 20 for 1st grade. Written to 1.OA.C.6, so students add and subtract on the question cards, then strike a suspect off the sheet until one name is left, which gives you math worksheets and math activities from one no prep download. Nothing in it is seasonal, so it runs from back to school in August through to the end of year. Color and black and white versions, with a full answer key and detective activities that get your class moving.\u003c\/p\u003e\n\n\u003cp\u003e\u003c!--LEAD--\u003eStudents will happily do a whole session of math facts if they are on their feet and there is a culprit at the end of it. The cards go up around the room, each answer takes a suspect off the sheet, and the class works its way round. Cut them once and you have an activity for every year after this one, ready for early finishers too.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Mischievous Magician\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe magician is up to something and the class has been called in. Students move from card to card, and each answer they solve rules out another suspect on the sheet they carry. The last name left when every card is done is the one behind it all.\u003c\/p\u003e\n\n\n\n\n\u003cp\u003e\u003cstrong\u003eWhat's Inside\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eEleven numbered question cards to put up around the room\u003c\/li\u003e\n  \u003cli\u003eAddition and subtraction within 20, written to 1.OA.C.6\u003c\/li\u003e\n  \u003cli\u003eA suspect sheet each student carries and crosses names off as they go\u003c\/li\u003e\n  \u003cli\u003eA color set and a black and white set of the same cards\u003c\/li\u003e\n  \u003cli\u003eThe answer key, with the culprit named\u003c\/li\u003e\n  \u003cli\u003ePrint, cut the cards once, and the set is ready for good\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\n\n\n\u003cp\u003e\u003cstrong\u003eWhat Is a CSI Mystery Detective?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA CSI Mystery Detective gives your class a crime, a lineup and a set 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 has not been ruled out. Run as SCOOT the questions go on the wall and students travel between them, which is what separates detective activities from a page of math worksheets. 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\u003eReach for this when the facts within 20 need another run and nobody will sit through a third worksheet. Sending students around the room turns the same eleven questions into a lesson they finish, and the suspect sheet makes each one matter because a wrong sum takes out the wrong person. It is also the folder to leave behind when you are out for the day.\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\n\n\n\u003cp\u003e\u003cstrong\u003eGrade Levels\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWritten for 1st grade, where 1.OA.C.6 sits in the standards. Kindergarten classes take it late in the year once addition within 10 is secure, and second graders use it as a start of year warm up before moving on to within 100.\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 are up and moving, which keeps first graders working\u003c\/li\u003e\n  \u003cli\u003eThe suspect sheet flushes out a wrong answer without you checking it\u003c\/li\u003e\n  \u003cli\u003eOne cut and the cards last for years\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\n\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\"\u003ehttps:\/\/www.teacherspayteachers.com\/Sellers-Im-Following\/Add\/Kiwiland\u003c\/a\u003e\u003c\/p\u003e","brand":"Kiwiland Education","offers":[{"title":"Default Title","offer_id":62593085473138,"sku":"9341122","price":4.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2848\/0626\/files\/addition-and-subtraction-within-20-scoot-task-cards_2f40c55a-9789-4cbd-b20c-11f511b8665c.jpg?v=1792612683"}],"url":"https:\/\/kiwilandeducation.com\/collections\/math-1-oa.oembed","provider":"Kiwiland Education","version":"1.0","type":"link"}