Fractions are used to express a part of a unit. Comparing fractions requires a calculation as they differ in size of the whole. For example 2/3 cannot be compared to 7/11 directly. When comparing fractions you must make sure that they have a common denominator (lower number), so that you can compare the top numbers. You can do this by making two multiplications and comparing the final numbers to find the larger number.
Things You'll Need
 Calculator

Check the two fractions to find the nearest common denominator. For example, the nearest common denominator for 1/3 and 2/5 is 15, as this is the first number that both 3 and 5 go into.

Multiply the first fraction by the required amount to get the common fraction. For example 1/3 to get to a bottom number of 15 needs to be multiplied by 5 giving the answer of 5/15.

Multiply the second fraction by the required amount to get the common fraction. For example 2/5 to get to a bottom number of 15 needs to be multiplied by 3 giving the answer of 6/15.

Compare the results. In the example case we find that the second fraction of 2/5 (6/15) is larger than 1/3 (5/15).