Adding & Subtracting Integers CSI Mystery Worksheets

Inside the case file

Adding and subtracting integers worksheets, positive and negative numbers practice, and integer addition and subtraction activities for 6th grade, 7th grade and 8th grade math are all included in this CSI Mystery Detective — a no-prep math activity. Students work through integer problems - adding a negative, subtracting a negative, and answers that land either side of zero - to eliminate suspects and work out which cash bag was taken from the bank vault. Perfect for middle school math centers, spiral review, test prep, sub days and independent practice, and completely no prep - just print and go.

Every clue is built on integer addition and subtraction, so students get negative number practice, sign work, and answers on both sides of zero woven through one story. A cash bag has gone from a bank vault that stayed locked all weekend, and only the math will say which one.

What's Inside

• Adding integers with unlike signs, where the answer can land either side of zero: -13 + 4, -25 + 6
• Subtracting a larger number from a smaller one so the answer goes negative: 26 - 40, 30 - 45
• Subtracting a negative and recognizing it as adding: 19 - (-2), 6 - (-37)
• Adding a negative and recognizing it as subtracting: 45 + (-8), 17 + (-4)
• Judging whether a given answer is correct, and catching the sign error when it is not
• Working a running chain of additions and subtractions that crosses zero again and again
• Matching integer problems to their answers and tracing a route through a number maze
• Complete answer keys
• Full color and ink-saving black and white versions of every page

One full-length case to crack, with every clue building on the last.

What is a CSI Mystery Detective?

A CSI Mystery Detective is a print-and-solve math activity - like an escape room without the locks. Students work through math problems to collect evidence, eliminate suspects, and reveal who did it. It combines real skill practice with critical thinking and a detective hook that keeps the whole class engaged.

When to Use This Resource

This integers CSI Mystery Detective can be used any time you are teaching or revisiting positive and negative numbers. Teachers love it for:

• Introducing or consolidating an integers unit
• Middle school math centers and small group rotations
• Warm-ups, morning work and early finishers
• Substitute teacher plans
• Integer review before state testing
• Homework and end-of-unit spiral practice
• Whole-class challenge days and enrichment

Grade Levels

Designed for 6th grade, 7th grade and 8th grade integer work. Also beneficial for 9th graders who still need confidence with negative numbers before algebra, and advanced 5th graders ready for a challenge.

Why Teachers Love CSI Mystery Detective packs

• Feels like a math escape room, with no locks and no technology required
• The detective storyline keeps students working through problem after problem
• Easy prep - simply print and go
• The pages check themselves - a wrong answer stops the mystery in its tracks, so students find their own mistake before it ever reaches your marking pile
• Works for independent practice, partners, small groups or a whole class challenge
• Builds integer fluency, reasoning and problem solving together

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