5th Grade Prime Factorization (Factor Trees) Worksheet — Level 1 — Practice Set 2 — Answers
Answer sheet with worked solutions for the 5th Grade factors, multiples & primes worksheet.
5th Grade Prime Factorization (Factor Trees) Worksheet — Level 1 — Practice Set 2 — 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 54 as a product of prime factors.
Answer: 2×3×3×3
- 54 = 2 × 27
- 27 = 3 × 9
- 9 = 3 × 3
- So 54 = 2 × 3 × 3 × 3 = 2 × 33
2.Use a factor tree to write 45 as a product of prime factors.
Answer: 3×3×5
- 45 = 3 × 15
- 15 = 3 × 5
- So 45 = 3 × 3 × 5 = 32 × 5
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.Use a factor tree to write 50 as a product of prime factors.
Answer: 2×5×5
- 50 = 2 × 25
- 25 = 5 × 5
- So 50 = 2 × 5 × 5 = 2 × 52
5.Use a factor tree to write 60 as a product of prime factors.
Answer: 2×2×3×5
- 60 = 2 × 30
- 30 = 2 × 15
- 15 = 3 × 5
- So 60 = 2 × 2 × 3 × 5 = 22 × 3 × 5
6.Use a factor tree to write 20 as a product of prime factors.
Answer: 2×2×5
- 20 = 2 × 10
- 10 = 2 × 5
- So 20 = 2 × 2 × 5 = 22 × 5
7.Use a factor tree to write 36 as a product of prime factors.
Answer: 2×2×3×3
- 36 = 2 × 18
- 18 = 2 × 9
- 9 = 3 × 3
- So 36 = 2 × 2 × 3 × 3 = 22 × 32
8.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
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.