Skip to content

Welcome guest

Please login or register
Skip to product information

Kiwiland Education

Back to School 3 Digit Addition with Regrouping Math Detective Mystery

$4.00 USD

3-digit addition with regrouping turns your class into crime-solving detectives in this no-prep Back to School Math Detective Mystery, where students crack three school-themed cases by working out who took the teacher's lunchbox, where the missing teacher went, and who swiped the art supplies. Every printable, self-checking case works the same clever way: students solve each 3-digit addition problem, use their answers to eliminate suspects from a police line-up, and the last suspect standing is the culprit. Perfect for 2nd, 3rd, and 4th grade back-to-school activities, math centers, morning work, homework, early finishers, substitute and relief days, indoor recess, spiral review, and the first weeks of school.

Quick Details

  • Skill: 3-digit addition with regrouping
  • Grades: 2nd, 3rd, 4th
  • Format: 3 detective cases + suspect line-ups + full answer keys (printable PDF, color and black-and-white)
  • Theme: Back to School / Detective

The 3 Cases

  • Case One: The Teachers Lunchbox — The teacher's lunchbox has gone missing. Students solve the addition problems and eliminate suspects to reveal who took it.
  • Case Two: The Missing Teacher — A teacher has vanished from school. Students crack the sums and work down the line-up to name who is responsible.
  • Case Three: The Missing Art Supplies — The art supplies have disappeared. Students add their way through the clues to unmask the culprit.

Why Teachers Love It

Zero prep — just print and hand out. The cases are completely self-checking, so students know they are on track without you marking every page. The detective line-up hook pulls in reluctant and struggling mathematicians, while the elimination structure makes differentiation and independent practice easy. Includes both full-color and black-and-white versions.

Skills Covered

3-digit addition with regrouping (carrying), multi-step problem solving, and logical reasoning through deductive suspect elimination.

What is Included

  • 3 detective case worksheets
  • Matching suspect line-up pages
  • Full answer keys for every case
  • Student detective instruction page
  • Color and black-and-white versions

Best Used For

No-prep printable 3-digit addition practice for back to school, math centers, morning work, homework, early finishers, sub days, indoor recess, and spiral review in 2nd, 3rd, and 4th grade.

All of our products are digital downloads — no physical items will be shipped.

  • After purchase, you’ll receive an email with a download link within minutes.
  • Make sure to check your spam or promotions folder if you don't see it right away.
  • If you experience any issues accessing your files, please contact us and we’ll help you promptly.

Due to the nature of digital products, all sales are final.

We do not offer refunds or exchanges once a file has been downloaded.

However, if you encounter any problems with your download or the product itself, please reach out — we're happy to assist.

  • Thank you from Kiwiland Education

How Math Mysteries Work

Each Math Mystery resource gives you five one-page cases that turn math practice into a clue-based investigation. Here's exactly how a case plays out.

CASE FILE 5 MYSTERIES

Every set is a ready-to-solve investigation

Students become the math detective. They read a story, crunch the numbers, and use their answers as evidence to rule out suspects — until only the culprit is left standing.

1
STEP 01

Read the Case

Each mystery opens with a short, themed story that sets the scene and tells students exactly what they're trying to find out — who took something, what went missing, or what really happened.

Hooks them in seconds
2
STEP 02

Solve the Problems

Students work through a set of problems built around the target skill. Every answer is a clue — so there's a real reason to get each one right.

Focused skill practice
3
STEP 03

Eliminate Suspects

Students match their answers against the suspect list and cross off names one clue at a time. Wrong math means the wrong suspect — so the activity self-checks as they go.

Self-checking built in
4
STEP 04

Crack the Case

One suspect is left — and students reveal who did it. The payoff makes review feel like a win, and they're ready to start the next case.

The satisfying reveal

See it in action

SOLVE A CLUEAnswer = 576
MATCH THE ANSWER576 = Bianca
CROSS OFFBianca
No apps. No logins. No prep. Just print, hand out, and let them investigate.

Why Teachers Use Math Mysteries

Skill practice that feels like a case worth solving — and a download that quietly does a lot of your planning for you.

5one-page cases per set
0prep or setup time
color & black-and-white
answer keys included

Five Mysteries in One

Every download includes five separate one-page cases — enough for a full week of practice, a center rotation, or a sub-day backup that's always ready to go.

Truly No-Prep

No cutting, laminating, apps, or logins. Print in full color or black-and-white and hand them straight out — that's the whole setup.

Self-Checking by Design

Students need the right answers to rule out the right suspects, so accuracy matters — and the included answer keys mean no grading for you.

Fits Any Routine

Use one case as a morning warm-up, or spread the five across the week for centers, partner work, early finishers, or intervention.

Keeps Students Hooked

The mystery format gives even reluctant mathematicians a reason to keep solving. Review starts to feel like a game, not another worksheet.

Differentiation-Friendly

Great for on-level practice, an extension for advanced students, or a targeted review pass for anyone who needs another go at the skill.

NO PREP PRINT & GO ANSWER KEYS INCLUDED

What's in every Math Mystery set

5 full-color mysteries 5 black-and-white versions 5 complete answer keys Print-and-go teacher page Bonus coloring page
Practice that feels like a case worth cracking.

Frequently Asked Questions About Math Mysteries

Printable Math Mystery worksheets that turn math practice into clue-based detective investigations.

Is this Math Mystery a digital activity?

No. This is a printable PDF resource. Students complete the Math Mystery on paper. No physical item will be shipped.

Do students need apps, locks, passwords, or logins?

No. Students do not need apps, locks, passwords, or logins. Teachers can print the pages and use the Math Mystery straight away.

How do students solve the Math Mystery?

Each resource includes five one-page cases. In each one, students solve the math problems and use their answers to eliminate suspects until only one remains and the case is cracked.

Can this Math Mystery be used for sub plans?

Yes. Math Mysteries work well for sub plans because students can work through the clues independently, with a partner, or in small groups.

Can this Math Mystery be used for homeschool?

Yes. This printable Math Mystery can be used for homeschool lessons, tutoring, review practice, enrichment, or extra math support.

Will this work for early finishers or math centers?

Yes. Math Mysteries are a good fit for early finishers, math centers, small groups, independent work, review lessons, and extra practice activities.



Back to School 3-digit addition with regrouping Math Detective Mystery for 2nd, 3rd and 4th grade - no-prep printable

Back to School 3 Digit Addition with Regrouping Math Detective Mystery

$4.00

Your Cart

Your Wishlist