Let's solve each pair of numbers for both the
Least Common Multiple (LCM) and the
Greatest Common Factor (GCF).
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🔹 Definitions:
-
GCF (Greatest Common Factor): The largest number that divides both numbers evenly.
-
LCM (Least Common Multiple): The smallest number that is a multiple of both numbers.
We’ll use prime factorization or listing methods where appropriate.
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1. 16, 10
- Prime factors:
- 16 = $2^4$
- 10 = $2 \times 5$
- GCF: common factor = $2$ →
GCF = 2
- LCM: take highest powers: $2^4 \times 5 = 16 \times 5 = 80$ →
LCM = 80
✔ LCM = 80,
GCF = 2
---
2. 14, 6
- Prime factors:
- 14 = $2 \times 7$
- 6 = $2 \times 3$
- GCF: common factor = $2$ →
GCF = 2
- LCM: $2 \times 3 \times 7 = 42$ →
LCM = 42
✔ LCM = 42,
GCF = 2
---
3. 3, 27
- Prime factors:
- 3 = $3$
- 27 = $3^3$
- GCF: $3$ →
GCF = 3
- LCM: $3^3 = 27$ →
LCM = 27
✔ LCM = 27,
GCF = 3
---
4. 6, 14
- Prime factors:
- 6 = $2 \times 3$
- 14 = $2 \times 7$
- GCF: $2$ →
GCF = 2
- LCM: $2 \times 3 \times 7 = 42$ →
LCM = 42
✔ LCM = 42,
GCF = 2
---
5. 16, 5
- Prime factors:
- 16 = $2^4$
- 5 = $5$
- GCF: no common factors →
GCF = 1
- LCM: $2^4 \times 5 = 16 \times 5 = 80$ →
LCM = 80
✔ LCM = 80,
GCF = 1
---
6. 8, 12
- Prime factors:
- 8 = $2^3$
- 12 = $2^2 \times 3$
- GCF: $2^2 = 4$ →
GCF = 4
- LCM: $2^3 \times 3 = 8 \times 3 = 24$ →
LCM = 24
✔ LCM = 24,
GCF = 4
---
7. 16, 6
- Prime factors:
- 16 = $2^4$
- 6 = $2 \times 3$
- GCF: $2$ →
GCF = 2
- LCM: $2^4 \times 3 = 16 \times 3 = 48$ →
LCM = 48
✔ LCM = 48,
GCF = 2
---
8. 8, 3
- Prime factors:
- 8 = $2^3$
- 3 = $3$
- GCF: no common factors →
GCF = 1
- LCM: $2^3 \times 3 = 8 \times 3 = 24$ →
LCM = 24
✔ LCM = 24,
GCF = 1
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✔ Final Answer Table:
| Numbers | LCM | GCF |
|--------|-----|-----|
| 16, 10 |
80 |
2 |
| 14, 6 |
42 |
2 |
| 3, 27 |
27 |
3 |
| 6, 14 |
42 |
2 |
| 16, 5 |
80 |
1 |
| 8, 12 |
24 |
4 |
| 16, 6 |
48 |
2 |
| 8, 3 |
24 |
1 |
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Let me know if you'd like this in printable format or with step-by-step diagrams!
Parent Tip: Review the logic above to help your child master the concept of lcm and gcf worksheet.