Year 5 Prime Factorisation (Factor Trees) Worksheet — Level 1 — Answers
Answer sheet with worked solutions for the Year 5 factors, multiples & primes worksheet.
Success TutoringWorksheetsAnswer sheetYear 5 · Mathematics · Factors, Multiples & PrimesYear 5 Prime Factorisation (Factor Trees) Worksheet — Level 1 — 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 18 as a product of prime factors.
Answer: 2×3×3
- 18 = 2 × 9
- 9 = 3 × 3
- So 18 = 2 × 3 × 3 = 2 × 32
2.Use a factor tree to write 12 as a product of prime factors.
Answer: 2×2×3
- 12 = 2 × 6
- 6 = 2 × 3
- So 12 = 2 × 2 × 3 = 22 × 3
3.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
4.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
5.Use a factor tree to write 24 as a product of prime factors.
Answer: 2×2×2×3
- 24 = 2 × 12
- 12 = 2 × 6
- 6 = 2 × 3
- So 24 = 2 × 2 × 2 × 3 = 23 × 3
6.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
7.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
8.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
Marking tips
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