2-Digit Addition with Regrouping | Mystery Detective Worksheets | Grades 1–3 | Valentine's Day

2 digit addition with regrouping worksheets for 1st grade and 2nd grade, five Valentines Day Mystery Detective math pages. February math activities, no prep, full answer keys, for math centers, morning work, early finishers, homework and sub plans, print and go. Flowers for the teacher, a mystery singer and a card with no signature carry the week, each total crosses a suspect off the lineup, and the carrying underneath is real practice that checks itself, and a CSI Mini Mystery Detective is what makes a six year old carry to the end of the page.

A young class will do far more addition when there is a name to find at the end, and a secret valentine is a name a first grader wants. The CSI Mini Mystery Detective math cases are short enough to finish in a morning work slot, and the marking is student-led, with the keys there for a quick glance.

The Cases

1. Flowers for the Teacher - flowers and no card with them
2. Valentine Songs - chocolates and a mystery singer
3. Un-named Flowers - the label has been torn off
4. Mindfulness Practice - somebody is keeping the class calm
5. Valentines Day Card - a card with no signature

What's Inside

• Five case files, each with a crime sheet and its own lineup of suspects
• Two digit addition with regrouping on every page
• Carrying on most problems, with space to write the ten above the column
• 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 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.

When to Use This Resource

February is the month, and the two or three days around Valentines Day are where a first or second grade class will do nothing that looks like work. These cases look like a puzzle and are actually a full page of carrying practice each. Miss the carry and the wrong suspect goes, which teaches the point faster than a correction in the margin ever does.

Use 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.

Grade Levels

Written for 1st grade and 2nd grade, where two digit addition with regrouping sits in the standards. Third graders take it as a February warm up, and first graders manage it once adding without carrying is secure.

Why Teachers Love These Cases

• Looks like a puzzle and works like a page of carrying practice
• Students learn from a missed carry the moment the wrong name goes
• No prep in the week of the class party
• Works with a whole class, a small group, partners, or one student alone

Love this resource?

Follow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no-prep math activities, and detective-themed printables for elementary classrooms.

Follow Kiwiland Education on TPT ↗