Prime and Composite Numbers

Inside the case file

Prime and composite numbers, factors and multiples, and factor pairs are the skills behind all ten cases in these 4th grade math Mini Mystery Detective worksheets. Use the factors and multiples practice pages in math centers, for morning work or with early finishers. They have a museum theme, and they're no prep. Every case comes with an answer key.

Use this pack once your class knows its multiplication facts. The cases take place in a museum after dark, with a stolen dinosaur egg and a walking mummy. Students find each answer on the suspect list and cross that name off, and every CSI Mini Mystery Detective page is self-checking.

What's Inside

• Ten one-page detective cases on factors, multiples, and prime and composite numbers, each with an answer key
• Missing factor and factor pair practice with numbers to 100
• Cases that ask for the factor or multiple, and cases that ask for the one that is NOT
• A mixed review case that brings all three skills together
• A reference page with worked examples for factors, multiples, prime and composite numbers
• A contents page, teacher instructions, a detective case log and a certificate of achievement
• 30 black and white pages, ready to print

The Cases

1. The Stolen Dinosaur Egg - find the missing factor
2. The Mummy That Walked - pick the factor
3. The Cracked Vase - spot what is not a factor
4. The Missing Diamond - pick the multiple
5. The Pharaoh's Lost Mask - spot what is not a multiple
6. The Muddy Footprints - skip count to the next multiple
7. The T. Rex That Roared - prime and composite to 60
8. The Blank Painting - find the next prime number
9. The Switched-Off Cameras - prime and composite to 100
10. The Knight's Missing Sword - mixed review

When to Use This Resource

The cases start with factors, then multiples, then prime and composite numbers. You can hand out one case a day through the unit, or pull a single page when a group needs more practice with one skill. The mixed case at the end shows you quickly who can tell a factor from a multiple and a prime from a composite number. It also works for guided math groups, homework, a prime and composite review before a test, sub plans, homeschool lessons, and back to school or end of year review.

Grade Levels

Written for 4th grade, where students find factor pairs, recognize multiples and decide whether a number is prime or composite, all with whole numbers to 100. It also makes a handy factors and multiples review for 5th grade before greatest common factor and least common multiple.

Why Teachers Love Mystery Detectives

• Ready to print
• A correct answer crosses off a suspect
• Cases build step by step, and different students can work on different pages
• A museum mystery with dinosaurs, mummies and missing treasure
• Easy to print in black and white

Want more cases like these?

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

https://www.teacherspayteachers.com/Sellers-Im-Following/Add/Kiwiland

Get it on TPT ↗