Year 5 Prime Factorisation (Factor Trees) Worksheet — Level 2 — 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 — 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 270 as a product of prime factors.
Answer: 2×3×3×3×5
- 270 = 2 × 135
- 135 = 3 × 45
- 45 = 3 × 15
- 15 = 3 × 5
- So 270 = 2 × 3 × 3 × 3 × 5 = 2 × 33 × 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 70 as a product of prime factors.
Answer: 2×5×7
- 70 = 2 × 35
- 35 = 5 × 7
- So 70 = 2 × 5 × 7
4.Which number has the prime factorisation 3 × 5 × 7?
Answer: 105
- 3 × 5 × 7 = 105
5.Use a factor tree to write 147 as a product of prime factors.
Answer: 3×7×7
- 147 = 3 × 49
- 49 = 7 × 7
- So 147 = 3 × 7 × 7 = 3 × 72
6.Use a factor tree to write 294 as a product of prime factors.
Answer: 2×3×7×7
- 294 = 2 × 147
- 147 = 3 × 49
- 49 = 7 × 7
- So 294 = 2 × 3 × 7 × 7 = 2 × 3 × 72
7.Use a factor tree to write 168 as a product of prime factors.
Answer: 2×2×2×3×7
- 168 = 2 × 84
- 84 = 2 × 42
- 42 = 2 × 21
- 21 = 3 × 7
- So 168 = 2 × 2 × 2 × 3 × 7 = 23 × 3 × 7
8.Which number has the prime factorisation 22 × 32?
Answer: 36
- 2 × 2 × 3 × 3 = 36
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