Determine whether or not the fraction is at its lowest terms by finding the Greatest Common Factor (GCF) between the numerator and denominator. For example, in the fraction 15/5 the denominator of five is capable of being evenly divided by 1 and 5 while the larger numerator of 15 can be divided by 1, 3, 5, and 15. The greatest number or factor both the numerator and denominator are evenly divided by is 5.
Divide both the numerator and denominator by the GCF. In the example of 15/5 with a GCF of 5, the reduced fraction is 3/1. The fraction 3/1 is further reduced to the whole number of 3 with the removal of the denominator.
Assess any leftover digits if your fraction was not reduced directly to a whole number. For example, the fraction 33/9 has a GCF of three, which reduces the fraction to 11/3. Some math problems require you to keep a fraction for future use while others support converting the fraction to a mixed number.
Divide the larger numerator of a fraction by the denominator to express the fraction as a mixed number. In the example of 11/3, the fraction is converted to 3 and 2/3. This is because the number 3 divides into 11 exactly three times while generating a remainder of 2 to be placed over the existing denominator.