**Fractions refer to the number of parts that equal the whole**.

Suppose we have a cake divided into equal portions, the fraction comes to represent each of the portions into which we have cut the cake. Thus, if we have four equal portions, each of them represents a quarter of the pie. This is expressed numerically as follows: $1 \over 4$.

The number $1$ refers to the specific slice of the total pie set. We can look at it in the following way: we are talking about one slice and, therefore, we express it with a $1$. If we were talking about two slices, instead of $1$ we would write $2$.

The number $4$ refers to all equal portions of the pie. Since we have divided the pie into four equal portions, the number that should represent this division is $4$.