How Do You Find the Prime Factorization of a Number?

There are a few different methods to find the prime factorization of a number, but one common method is to use a process called the ladder method. This involves dividing the number in question by the smallest prime number (usually 2) and then continuing to divide the quotient by prime numbers until the quotient is itself a prime number. The prime factorization is then the list of all the prime numbers used in the division process, along with their corresponding powers.

What Is a Factor Tree?

Another method to find prime factorization is by using factor trees. A factor tree is a visual tool used to find the prime factorization of a number. It is a tree-like diagram that starts with the number in question and repeatedly breaks it down into smaller factors until all the factors are prime numbers.

To create a factor tree, start by writing the number in question at the top of a blank page or whiteboard. Then, you divide the number by a small prime factor (usually 2) and write the quotient and remainder on the branches below the original number. Next, you repeat the process with the quotient and continue to divide it by prime factors, writing the quotient and remainder on the branches below. The process is continued until all the factors are prime numbers.

Teach Starter has created an interactive activity that will keep your students engaged while practicing this important 6th-grade math skill.

Tips for Differentiation + Scaffolding 

A team of dedicated, experienced educators created this resource to support your math lessons.

In addition to individual student work time, use this activity to enhance learning through guided math groups, whole class lessons, or remote learning assignments. 

If you have a mixture of above and below-level learners, we have a few suggestions for keeping students on track with these concepts: 

🆘 Support Struggling Students

Allow for the use of completed examples and notes, multiplication chart, and/ or calculator. Work one on one or allow peer tutors.

➕ Challenge Fast Finishers

For students needing a challenge, edit some of the slides to include larger numbers. Also, when students are done, they can be encouraged to make their own how-to tutorial about prime factorization to share with the class.

Easily Prepare This Resource for Your Students

Use the Download button to access the interactive Google Slides version of this resource. An answer key is also provided for easy grading!

Assign this interactive activity in Google Classroom. Please be sure to open in Edit mode, not presentation mode. Students will drag and drop, extend lines, use the paint bucket tool, and type in responses to complete the activities.

This resource was created by Lorin Davies, a teacher in Texas and a Teach Starter Collaborator. 

While you’re here, check out more activities and teaching resources that fill your lesson plans and students’ brains:

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Prime Factorization – Task Cards

Practice how to find the prime factorization of a number with this set of 24 task cards

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Prime Factorization Match-Up

Practice how to find the prime factorization of a number with this match-up activity.