A fraction describes part of a whole. Let’s look at a pie cut into 4 equal slices. The pie is the whole and we’ve divided the whole into 4 equal parts.
If 1 slice is eaten and 3 are left, what fraction of the pie is left?
The bottom number, known as the denominator, shows the total number of slices. The top number, or numerator, shows the number of parts we’re talking about.