7th Grade Prime Factorization (Factor Trees) Worksheet — Level 2 — Answers
Answer sheet with worked solutions for the 7th Grade factors, multiples & primes worksheet.
Success TutoringWorksheetsAnswer sheet7th Grade · Mathematics · Factors, Multiples & Primes7th Grade Prime Factorization (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 45 as a product of prime factors.
Answer: 3×3×5
- 45 = 3 × 15
- 15 = 3 × 5
- So 45 = 3 × 3 × 5 = 32 × 5
2.Use a factor tree to write 72 as a product of prime factors.
Answer: 2×2×2×3×3
- 72 = 2 × 36
- 36 = 2 × 18
- 18 = 2 × 9
- 9 = 3 × 3
- So 72 = 2 × 2 × 2 × 3 × 3 = 23 × 32
3.Use a factor tree to write 150 as a product of prime factors.
Answer: 2×3×5×5
- 150 = 2 × 75
- 75 = 3 × 25
- 25 = 5 × 5
- So 150 = 2 × 3 × 5 × 5 = 2 × 3 × 52
4.Which number has the prime factorization 22 × 3 × 7?
Answer: 84
- 2 × 2 × 3 × 7 = 84
5.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
6.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
7.Use a factor tree to write 100 as a product of prime factors.
Answer: 2×2×5×5
- 100 = 2 × 50
- 50 = 2 × 25
- 25 = 5 × 5
- So 100 = 2 × 2 × 5 × 5 = 22 × 52
8.Which number has the prime factorization 32 × 7?
Answer: 63
- 3 × 3 × 7 = 63
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