4-Digit Addition with Regrouping

Inside the case file

4 digit addition with regrouping Valentines Day math worksheets for 3rd grade and 4th grade, five Mystery Detective math cases with carrying across four columns on every page. No prep February math activities with full answer keys, for math centers, early finishers, homework, morning work and sub plans, print and go. Valentines Day math for 3rd grade and 4th grade, with 4 digit addition with regrouping on every page and a school valentine mystery holding it together. It is a full week of February math activities for math centers, morning work or homework, and every CSI Mini Mystery Detective page is self-marking.

Carrying across four columns needs a full week of practice, not one page, and five CSI Mini Mystery Detective math cases with a valentine mystery in each are the week. Students add, match the total to a name and cross it off, which keeps everyone moving at their own pace, and the whole set is self-marking.

The Cases

1. Mystery Chocolates - a box and not a word from anyone
2. Valentines Day Card - a card with no signature
3. Valentines Day Flowers - left for the teacher overnight
4. Love Songs - somebody is singing love songs
5. Showing Mindfulness - quiet good deeds around the school

What's Inside

• Five case files, each with a crime sheet and its own lineup of suspects
• Four digit addition with regrouping on every page
• Carrying across four columns, a real step up from three digit work
• Each answer matches one suspect and no other, so the page checks itself
• A full answer key for every case
• Print and go: no cutting, no laminating, nothing to prepare

What Is a CSI Mini Mystery Detective?

A 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.

When to Use This Resource

Use this once three digit carrying is secure and the class is ready for the extra column, which lands around February for most third grade rooms. The Valentines setting gives you the reason to hand it out that week, and the skill keeps it useful right through to testing. A carry missed in the thousands names the wrong suspect, so students check the whole sum again rather than the last digit.

Teachers use it for test prep, homework, math centers, morning work, early finishers, sub plans and homeschool lessons, with a class, a small group or one student.

Grade Levels

Written for 3rd grade and 4th grade, where four digit addition sits in the standards. Fifth graders take it as a quick refresher, and second graders manage it once three digit carrying is secure.

Why Teachers Love These Cases

• Steps up to four columns, which most February resources do not
• Students recheck the whole sum when the wrong name comes off
• No prep, and the answer keys make grading quick
• Works with a whole class, a small group, partners, or one student alone

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