70

20

70

20

60

20

10

20

10

20

3

10

20

3

10÷2

20÷2

3

5

10

3

5÷5

10÷5

3

1

2

or

70

20

60

20

10

20

10

20

3

10

20

3

10

20

3

2 × 5

2 × 2 × 5

3

3

1

2

or

Common Divisors for 10 and 20 are: 2 and 5

Greatest Common Divisor = 2 × 5 = 10

3

70÷10

20÷10

3

1

2