Year 5 Prime Factorisation (Factor Trees) Worksheet — Level 2 — Practice Set 4 — 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 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 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
2.Use a factor tree to write 105 as a product of prime factors.
Answer: 3×5×7
- 105 = 3 × 35
- 35 = 5 × 7
- So 105 = 3 × 5 × 7
3.Use a factor tree to write 200 as a product of prime factors.
Answer: 2×2×2×5×5
- 200 = 2 × 100
- 100 = 2 × 50
- 50 = 2 × 25
- 25 = 5 × 5
- So 200 = 2 × 2 × 2 × 5 × 5 = 23 × 52
4.Which number has the prime factorisation 22 × 3 × 52?
Answer: 300
- 2 × 2 × 3 × 5 × 5 = 300
5.Use a factor tree to write 280 as a product of prime factors.
Answer: 2×2×2×5×7
- 280 = 2 × 140
- 140 = 2 × 70
- 70 = 2 × 35
- 35 = 5 × 7
- So 280 = 2 × 2 × 2 × 5 × 7 = 23 × 5 × 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 63 as a product of prime factors.
Answer: 3×3×7
- 63 = 3 × 21
- 21 = 3 × 7
- So 63 = 3 × 3 × 7 = 32 × 7
8.Which number has the prime factorisation 22 × 3 × 5?
Answer: 60
- 2 × 2 × 3 × 5 = 60
Marking tips
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