What I always do to solve this, is find a common factor for each number first.
Usually 4 or 5 works best. I'll use 4.
4 goes into 80 20 times, which means that 4 = 5% of 80.
If 4 = 5%, and 48 = 12 x 4, then 48 must equal 60% of 80.
(Another way to solve this problem is: simplify 48 / 80. This simplifies to 3/5.
3/5 = 60%)!
