1. High common
Factor( HCF )

2. Factors and multiplies
8
EXAMPLE 1
Factors :
1, 2, 4, 8
Multiple:
8, 16, 24, 32

3. Now find the factor and
multiple of 10!
10
Factors :
Multiple:

4. Now find the factor and
multiple of 10!
10
Factors :
1, 2, 5, 10
Multiple:
10,20,30,40

5. Example 1: HCF of 10 and 15
Factors of 10: 1, 2, 5
Factors of 15: 1, 3, 5
Common factors of 10 and 15 : 1, 5
HCF of 10 and 15: 5 (1 x 5)

6. Example 2: HCF of 24 and 36
Prime factors of 24: 1, 2, 3, 4, 6, 8, 12
Prime factors of 36: 1, 2, 3, 4, 6, 12
Common prime factors: 12
HCF =12

7. Now try finding the HCF of
12 and 16

8. HCF of 9 and 15
Prime factors of 9: 1, 3, 9
Prime factors of 15: 1, 3, 5
Common prime factors: 3
HCF = 3

9. Now try finding the HCF of
8 and 12