Several questions on the GED math test will require you to understand and know how to work with fractions. Fractions are normally used to express parts of a whole number. The names for the two parts of a fraction are the numerator , for the top part, and the denominator , for the bottom part. So in the fraction ½ the numerator is 1 and the denominator is 2. To give a real life example, imagine a pie cut into 8 slices. The pie is still one whole, however it is divided into 8 parts. 8/8 = 1. If three of the slices are eaten, the pie is no longer one whole and you can represent the remaining amount as 5/8.