Which is bigger 2/3 or 7/8

7/8 is bigger because if you change them to common denominators 2/3 would equal 16/24 and 7/8 would equal to 21/24 and 21/24 is greater than 16/24

To compare fractions is easier to do if they have the same denominator, so we make both fractions to share the same denominator, for this we need to find the minimum common multiple of 3 an 8 which is 24, hence we multiply and divide (for not alterating it) each fraction for a adequate multiplier:

(2/3) (8/8) = 2*8/3*8 = 16/24

(7/8) (3/3) = 7*3/8*3 = 21/24

Now we can easily compare:

21/24 > 16/24

21/24 = 7/8 is bigger