Math Worksheet · Grades 4–7
Prime Factorization Worksheet
A printable math worksheet for grades 4-7 on prime factorization. Students use factor trees to write six numbers as products of primes, then build trees and reason about four more. A complete answer key is included.
Subject
Math
Grades
Grades 4–7
Skill Focus
Prime Factorization, place value
Lesson Length
20 minutes
Lesson Overview
About this worksheet
Prime factorization breaks a number down into the prime numbers that multiply to make it. A factor tree is the tool: split a number into factors and keep splitting until every branch is prime. This worksheet builds that skill and shows how exponents record repeated primes.
The reference box and Section A are on page 1. The reference box walks through a factor tree with two worked examples. Section A has six numbers to factor into primes. Section B on page 2 has four problems: two factor trees, one comparison, and one prime check.
Page 3 is a complete answer key that shows each prime factorization and the reasoning for every word problem. The worksheet pairs well with the Factors and Multiples and Prime and Composite Numbers worksheets.
How to Use This Lesson
Read the reference box and follow the two factor-tree examples.
Factor the six numbers in Section A on page 1, using exponents for repeats.
Solve the four problems in Section B on page 2, showing each factor tree.
Use the answer key on page 3 for self-check.
Pair with the Factors and Multiples Worksheet.
Printable Resource
A classroom-ready PDF with everything in one printable resource.
Full Member Resource · Printable PDF · 3 pages · Answer Key
Prime Factorization Worksheet
A printable math worksheet for grades 4-7 on prime factorization. Students use factor trees to write six numbers as products of primes, then build trees and reason about four more. A complete answer key is included.
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