Sure! Let’s solve each problem step by step. The
Least Common Multiple (LCM) of two numbers is the smallest positive number that is a multiple of both.
There are several methods to find LCM:
-
Listing multiples (good for small numbers)
-
Prime factorization (most reliable)
-
Using the formula:
`LCM(a, b) = (a × b) / GCF(a, b)`
(GCF = Greatest Common Factor)
I’ll use prime factorization and/or the formula for accuracy.
---
1) LCM(8, 12)
Prime factors:
- 8 = 2³
- 12 = 2² × 3
Take highest power of each prime:
→ 2³ × 3 = 8 × 3 =
24
✔ Answer: 24
---
2) LCM(20, 40)
Note: 40 is a multiple of 20 → so LCM is
40
Check with formula:
GCF(20, 40) = 20
LCM = (20 × 40) / 20 = 40
✔ Answer: 40
---
3) LCM(22, 6)
Prime factors:
- 22 = 2 × 11
- 6 = 2 × 3
LCM = 2 × 3 × 11 =
66
✔ Answer: 66
---
4) LCM(14, 4)
Prime factors:
- 14 = 2 × 7
- 4 = 2²
LCM = 2² × 7 = 4 × 7 =
28
✔ Answer: 28
---
5) LCM(42, 30)
Prime factors:
- 42 = 2 × 3 × 7
- 30 = 2 × 3 × 5
LCM = 2 × 3 × 5 × 7 =
210
✔ Answer: 210
---
6) LCM(24, 32)
Prime factors:
- 24 = 2³ × 3
- 32 = 2⁵
LCM = 2⁵ × 3 = 32 × 3 =
96
✔ Answer: 96
---
7) LCM(15, 9)
Prime factors:
- 15 = 3 × 5
- 9 = 3²
LCM = 3² × 5 = 9 × 5 =
45
✔ Answer: 45
---
8) LCM(45, 27)
Prime factors:
- 45 = 3² × 5
- 27 = 3³
LCM = 3³ × 5 = 27 × 5 =
135
✔ Answer: 135
---
9) LCM(34, 26)
Prime factors:
- 34 = 2 × 17
- 26 = 2 × 13
LCM = 2 × 13 × 17 = 26 × 17 =
442
✔ Answer: 442
---
10) LCM(10, 48)
Prime factors:
- 10 = 2 × 5
- 48 = 2⁴ × 3
LCM = 2⁴ × 3 × 5 = 16 × 3 × 5 = 48 × 5 =
240
✔ Answer: 240
---
##
✔ Final Answers:
1)
24
2)
40
3)
66
4)
28
5)
210
6)
96
7)
45
8)
135
9)
442
10)
240
Let me know if you’d like to see the step-by-step using another method (like listing multiples or GCF formula) for any of them!
Parent Tip: Review the logic above to help your child master the concept of lcm worksheets.