20

16

20

16

16

16

4

16

4

16

1

4

16

1

4÷2

16÷2

1

2

8

1

2÷2

8÷2

1

1

4

or

20

16

16

16

4

16

4

16

1

4

16

1

4

16

1

2 × 2

2 × 2 × 2 × 2

1

1

1

4

or

Common Divisors for 4 and 16 are: 2 and 2

Greatest Common Divisor = 2 × 2 = 4

1

20÷4

16÷4

1

1

4