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• Printable Factor Tree Worksheets in PDF: Prime Factorization Practice

Printable Factor Tree Worksheets in PDF: Prime Factorization Practice

A factor tree breaks a number down into its prime factors by splitting it into smaller factors, branch by branch, until every branch ends in a prime number. These free grade 6 worksheets give students practice building factor trees for a range of numbers, and every printable PDF includes a full answer key. For more factorization practice, see Brighterly’s Factors and Multiples Worksheets collection.

Factor Tree Worksheets: Free Download

This topic is available as four downloadable worksheet files:

How to Build a Factor Tree

1. Write the number at the top of the tree.
2. Split it into two factors (not 1 or the number itself) and draw branches down to them.
3. If a factor is prime, circle it and stop that branch.
4. If a factor isn’t prime, keep splitting it into smaller factors.
5. Continue until every branch ends in a circled prime number.

Worked Example: Factor Tree for 28

• 28
  • 4
    • 2 (prime)
    • 2 (prime)
  • 7 (prime)

Since every branch ends in a prime number, the prime factorization of 28 is 2 × 2 × 7, or 2² × 7.

More Factors and Multiples Worksheets

• Factors and Multiples Worksheets
• Greatest Common Factor Worksheets
• Least Common Multiple Worksheets

Need a refresher on the underlying concept first? Check out this specific new Brighterly’s prime factorization overview before diving into the worksheets.

Benefits of These Factor Tree Worksheets

• Come with a full answer key
• Strengthens wider math skills like factorization and prime factors
• Predefined trees make the concept easier to grasp before working from scratch
• Created by qualified math tutors

By learning to use factor trees, kids strengthen their knowledge of a range of related math concepts — not just factor trees themselves, but the core ideas of factorization and prime numbers that show up throughout later math.

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Factor Tree Worksheets: FAQ

What is a factor tree?

A factor tree is a diagram that breaks a number down into its prime factors by splitting it into smaller factors, branch by branch. You write the number at the top, split it into two factors, and keep splitting any factor that isn’t prime until every branch ends in a circled prime number.

What grade are these factor tree worksheets for?

This set of factor tree worksheets is designed for grade 6 students who are learning prime factorization and how factor trees connect to multiplication and division. The predefined trees give students a clear, structured way to practice finding prime factors before building factor trees entirely from scratch on their own.

Do these worksheets include an answer key?

Yes, every factor tree worksheet in this set includes a full answer key. This lets kids check their completed trees against the correct prime factorization, building independent study skills and giving parents or teachers an easy way to review a student’s work without solving each full tree by hand themselves.

What other worksheets pair well with factor tree practice?

This worksheet pairs well with Brighterly’s wider factors and multiples cluster, including greatest common factor worksheets and least common multiple worksheets, since all three build on the same prime factorization skills. Students who want a quick refresher on the underlying concept can also check out Brighterly’s prime factorization overview page.