Simplifying a fraction means writing the fraction using smaller numbers – in its simplest form. This can also be called reducing a fraction or expressing a fraction in its lowest terms. The purpose of this is to make the numerator and denominator smaller numbers which are easier to calculate with.

To simplify a fraction, we find the highest common factor (HCF) - the highest number by which we can divide both the numerator and denominator. After dividing both parts of the fraction by the HCF, it is in its simplest form.

A fraction can also be simplified in several steps by finding common factors that are not the highest.