6th Grade Prime Factorization (Factor Trees) Worksheet — Level 2 — Practice Set 4 — Answers
Answer sheet with worked solutions for the 6th Grade factors, multiples & primes worksheet.
6th Grade Prime Factorization (Factor Trees) Worksheet — Level 2 — Practice Set 4 — Answers
Keep splitting each number into two factors until every branch ends in a prime. Write the primes from smallest to largest.
1.Use a factor tree to write 75 as a product of prime factors.
Answer: 3×5×5
- 75 = 3 × 25
- 25 = 5 × 5
- So 75 = 3 × 5 × 5 = 3 × 52
2.Use a factor tree to write 126 as a product of prime factors.
Answer: 2×3×3×7
- 126 = 2 × 63
- 63 = 3 × 21
- 21 = 3 × 7
- So 126 = 2 × 3 × 3 × 7 = 2 × 32 × 7
3.Use a factor tree to write 30 as a product of prime factors.
Answer: 2×3×5
- 30 = 2 × 15
- 15 = 3 × 5
- So 30 = 2 × 3 × 5
4.Which number has the prime factorization 23 × 7?
Answer: 56
- 2 × 2 × 2 × 7 = 56
5.Use a factor tree to write 56 as a product of prime factors.
Answer: 2×2×2×7
- 56 = 2 × 28
- 28 = 2 × 14
- 14 = 2 × 7
- So 56 = 2 × 2 × 2 × 7 = 23 × 7
6.Use a factor tree to write 84 as a product of prime factors.
Answer: 2×2×3×7
- 84 = 2 × 42
- 42 = 2 × 21
- 21 = 3 × 7
- So 84 = 2 × 2 × 3 × 7 = 22 × 3 × 7
7.Use a factor tree to write 42 as a product of prime factors.
Answer: 2×3×7
- 42 = 2 × 21
- 21 = 3 × 7
- So 42 = 2 × 3 × 7
8.Which number has the prime factorization 2 × 3 × 5?
Answer: 30
- 2 × 3 × 5 = 30
Marking tips
- Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
- For open-ended tasks, use the success criteria as a checklist rather than looking for one "right" answer.
- Celebrate what went well first, then pick one thing to work on next.