Let's solve each problem step by step to find the
Greatest Common Factor (GCF) of the given pairs of numbers.
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What is the Greatest Common Factor (GCF)?
The GCF of two numbers is the largest number that divides both of them without leaving a remainder.
We’ll use
prime factorization or
listing factors to find the GCF for each pair.
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1) 2 & 4
- Factors of 2: 1, 2
- Factors of 4: 1, 2, 4
- Common factors: 1, 2
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GCF = 2
✔ Answer: 2
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2) 3 & 9
- Factors of 3: 1, 3
- Factors of 9: 1, 3, 9
- Common factors: 1, 3
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GCF = 3
✔ Answer: 3
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3) 4 & 20
- Factors of 4: 1, 2, 4
- Factors of 20: 1, 2, 4, 5, 10, 20
- Common factors: 1, 2, 4
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GCF = 4
✔ Answer: 4
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4) 35 & 49
Let’s use prime factorization:
- 35 = 5 × 7
- 49 = 7 × 7
- Common prime factor: 7
-
GCF = 7
✔ Answer: 7
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5) 7 & 49
- 7 = 7
- 49 = 7 × 7
- Common factor: 7
-
GCF = 7
✔ Answer: 7
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✔ Final Answers:
1) 2
2) 3
3) 4
4) 7
5) 7
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You can fill these in the blanks on the worksheet accordingly. Let me know if you'd like a printable version or explanation with diagrams!
Parent Tip: Review the logic above to help your child master the concept of gcf worksheet 5th grade.
