Question

A pie was cut into 8 equal slices if Ruben ate 3/4 of the pie how many slices did he eat

Answer 1

We know there are 8 equal slices. There are 4 parts to the pie.
8 ÷ 4 = 2
We now know each part of the pie has 2 slices
Ruben ate 3/4 of the slices so,
2 x 3 = 6
6 is your numerator (top) (standing for how much Ruben ate)
8 is your denominator (bottom) (standing for total slices)
6 slices was eaten by Ruben
If you want to check your work, divide the numerator and denominator by 2 - since there are 2 equal slices per part
6 ÷ 2 = 3
8 ÷ 2 = 4
3/4 of the pie has been eaten.

Answer 2

You can just set 3/4=X/8, when you multiply the 4 through you get 3=4x/8 which can be simplified to 3=x/2, multiply the 2 over and you have 6=x.

Hope this helps :)