72

84

72

84

72÷2

84÷2

36

42

36÷2

42÷2

18

21

18÷3

21÷3

6

7

or

72

84

2 × 2 × 2 × 3 × 3

2 × 2 × 3 × 7

6

7

or

Common Divisors for 72 and 84 are: 2, 2 and 3

Greatest Common Divisor = 2 × 2 × 3 = 12

72÷12

84÷12

6

7

See 6/7 as a percent