20

32

20

32

20÷2

32÷2

10

16

10÷2

16÷2

5

8

or

20

32

2 × 2 × 5

2 × 2 × 2 × 2 × 2

5

8

or

Common Divisors for 20 and 32 are: 2 and 2

Greatest Common Divisor = 2 × 2 = 4

20÷4

32÷4

5

8

See 5/8 as a percent