Let’s solve each problem step by step. We’re finding the
Lowest Common Multiple (LCM) of two numbers for each pair.
The LCM is the smallest number that both numbers can divide into evenly.
We’ll go one by one:
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1. 4 and 22
Multiples of 4: 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44...
Multiples of 22: 22, 44, 66...
→ First common multiple:
44
✔ LCM = 44
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2. 6 and 24
Multiples of 6: 6, 12, 18, 24, 30...
Multiples of 24: 24, 48...
→ First common multiple:
24
✔ LCM = 24
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3. 8 and 6
Multiples of 8: 8, 16, 24, 32...
Multiples of 6: 6, 12, 18, 24, 30...
→ First common multiple:
24
✔ LCM = 24
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4. 3 and 4
Multiples of 3: 3, 6, 9, 12, 15...
Multiples of 4: 4, 8, 12, 16...
→ First common multiple:
12
✔ LCM = 12
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5. 10 and 23
23 is a prime number. So multiples of 23: 23, 46, 69, 92, 115, 138, 161, 184, 207, 230...
Check if any are divisible by 10 → only when it ends in 0 → 230
Is 230 ÷ 10 = 23? Yes.
So LCM = 230
✔ LCM = 230
*(Alternatively: since 10 and 23 share no common factors except 1, LCM = 10 × 23 = 230)*
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6. 2 and 4
Multiples of 2: 2, 4, 6, 8...
Multiples of 4: 4, 8, 12...
→ First common multiple:
4
✔ LCM = 4
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7. 16 and 24
List multiples:
16: 16, 32, 48, 64...
24: 24, 48, 72...
→ First common multiple:
48
✔ LCM = 48
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8. 28 and 6
Multiples of 28: 28, 56, 84, 112...
Multiples of 6: 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84...
→ First common multiple:
84
✔ LCM = 84
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9. 10 and 19
19 is prime. No common factors with 10.
So LCM = 10 × 19 =
190
✔ LCM = 190
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10. 14 and 28
28 is a multiple of 14 → so LCM is
28
✔ LCM = 28
---
11. 7 and 3
Both prime, no common factors.
LCM = 7 × 3 =
21
✔ LCM = 21
---
12. 4 and 29
29 is prime. No common factors with 4.
LCM = 4 × 29 =
116
✔ LCM = 116
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13. 19 and 9
19 is prime. 9 = 3×3. No common factors.
LCM = 19 × 9 =
171
✔ LCM = 171
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14. 9 and 11
Both primes relative to each other (no common factors).
LCM = 9 × 11 =
99
✔ LCM = 99
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Final Answer:
1. 44
2. 24
3. 24
4. 12
5. 230
6. 4
7. 48
8. 84
9. 190
10. 28
11. 21
12. 116
13. 171
14. 99
Parent Tip: Review the logic above to help your child master the concept of lcm worksheet 5th grade.
