common denominator

This is the term used for the identical denominators of two or more fractions.

The denominators have to be the same before we can add or subtract fractions.

A common denominator can be discovered by attempting different multiples which form equivalent fractions.

We can use $\frac{1}{3}$ and $\frac{1}{2}$ as an example.

Remember, the denominators have to be the same, so it isn’t possible to add $\frac{1}{3}$ and $\frac{1}{2}$ as they are. However, it is possible to use equivalent fractions for $\frac{1}{3}$ and $\frac{1}{2}$ in order to add them.

We can multiply $\frac{1}{3}$ by $\frac{2}{2}$ to get $\frac{2}{6}$ .

Then, we can multiply $\frac{1}{2}$ by $\frac{3}{3}$ to get $\frac{3}{6}$ .

The denominators of the fractions are now the same, therefore we can add $\frac{2}{6}$ and $\frac{3}{6}$ to get $\frac{5}{6}$ .

Therefore, $\frac{1}{3}$ + $\frac{1}{2}$ gives $\frac{5}{6}$ .

Mathematics

glossary of terms

common denominator