Reciprocal Fractions

To find the reciprocal of a fraction, flip it over, so that the numerator becomes the denominator and the denominator becomes the numerator. That is:

The reciprocal of 4/5 is 5/4

Note that the product of a fraction and its reciprocal is always 1.

4/5 x 5/4 = 20/20 = 1

In the case of a whole number, think of it as having a denominator of 1:

The reciprocal of 5 is 1/5.
5/1 x 1/5 = 5/5 = 1

Every number has a reciprocal except for 0. There is nothing you can multiply by 0 to create a product of 1, so it has no reciprocal.

Reciprocals are used when dividing fractions.

Multiplying Fractions and Mixed Numbers Dividing Fractions