12/15 = 80%
A value like 80% can show up in everyday life as a quiz score, a phone battery level, or a discount on a store sign. It tells you that something is at four-fifths of the whole.
To picture 12/15 quickly, imagine 15 equal slices of pizza with 12 taken or filled in. That is most of the pizza, with only 3 slices left out.
One common point of confusion is thinking 80% means 80 out of 100 separate items, even when the total is different. The percent describes a share of the whole, so the total number of items can vary.
