80

30

80

30

60

30

20

30

20

30

2

20

30

2

20÷2

30÷2

2

10

15

2

10÷5

15÷5

2

2

3

or

80

30

60

30

20

30

20

30

2

20

30

2

20

30

2

2 × 2 × 5

2 × 3 × 5

2

2

2

3

or

Common Divisors for 20 and 30 are: 2 and 5

Greatest Common Divisor = 2 × 5 = 10

2

80÷10

30÷10

2

2

3