7th Grade Prime Factorization (Factor Trees) Worksheet — Level 2 — Practice Set 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 — 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 98 as a product of prime factors.
Answer: 2×7×7
- 98 = 2 × 49
- 49 = 7 × 7
- So 98 = 2 × 7 × 7 = 2 × 72
2.Use a factor tree to write 48 as a product of prime factors.
Answer: 2×2×2×2×3
- 48 = 2 × 24
- 24 = 2 × 12
- 12 = 2 × 6
- 6 = 2 × 3
- So 48 = 2 × 2 × 2 × 2 × 3 = 24 × 3
3.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
4.Which number has the prime factorization 3 × 72?
Answer: 147
- 3 × 7 × 7 = 147
5.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
6.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
7.Use a factor tree to write 245 as a product of prime factors.
Answer: 5×7×7
- 245 = 5 × 49
- 49 = 7 × 7
- So 245 = 5 × 7 × 7 = 5 × 72
8.Which number has the prime factorization 22 × 3 × 7?
Answer: 84
- 2 × 2 × 3 × 7 = 84
Marking tips
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