Dividing Decimals | Mystery Detective Worksheets | Grades 4–7 | Printable Detective Pack

Dividing decimals worksheets for 5th grade and 6th grade, five CSI Mini Mystery Detective math cases where each quotient rules a suspect out until one name is left. Written to 5.NBT.7, so every page is decimal division practice that checks itself, because a misplaced decimal point lands on no suspect at all. Print and go with full answer keys: math activities for the decimals unit, then math centers, early finishers, homework, morning work, test prep and sub plans any month of the year.

Decimal division is the last stop in the decimals unit and the one most likely to come up again at test time, which is why a set you can reuse matters. Students divide, match the quotient to a name and cross it off, so they catch a slipped decimal point themselves before you see it. Use one CSI Mini Mystery Detective math case with the whole class and keep four for spiral review.

The Cases

1. The Missing Gem - a rare gem vanishes without trace
2. Mythical Potion - the recipe vanishes into thin air
3. Championship Football - the game ball taken before kickoff
4. Underwater Research Station - the station has been broken into
5. The Bakery - the bakery loses its prize recipe

What's Inside

• Five case files, each with a crime sheet and its own lineup of suspects
• Dividing decimals on every page, written to 5.NBT.7
• Divisors and dividends that both carry decimals, so the point has to be moved correctly
• 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 hands your class a crime and a lineup of suspects, and the way through it is the math. Work the crime sheet, match each answer to the suspect wearing that number, cross that name off, and keep going until one suspect has not been ruled out. Because the elimination depends on the arithmetic being right, these detective activities catch errors a page of math worksheets would let through. One case takes a class period.

When to Use This Resource

Decimal division is the last thing in the unit and usually the part with the least practice time left, so this is the set that fills that gap. Use it once students can divide whole numbers and are learning to shift the point before they start. Getting the point in the wrong place crosses off the wrong suspect, which makes the error visible instead of it sitting quietly in a column of answers.

It carries test prep, homework, math centers, morning work, early finishers, sub plans, homeschool lessons and spiral review, with a class, a small group or one student.

Grade Levels

Written for 5th grade, where 5.NBT.7 sits, and used with 6th graders as fluency practice. Fourth graders take it once decimal place value is secure, and 7th graders use it as a refresher before percentages and unit rates.

Why Teachers Love These Cases

• All about moving the decimal point, which is where students come unstuck
• Students see the error themselves when the wrong suspect 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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