Subtract Fractions with Unlike Denominators

Use the least common denominator to find the difference between fractions with unlike denominators.

For example: Let's find the difference of:

5 6

and

1 2

Notice that 6 is the common denominator.

First of all, rewrite the fraction having common denominator 6.

Multiply the numerator and denominator of

1 2

by 3 to find an equivalent fraction.

1 2

×

3 6

=

3 6

Now subtract fractions. Subtract numerators and keep denominators the same.

5 6

–

1 2

=

5 6

–

3 6

=

2 6

is not written in simplest form.

 

2 6

÷

2 2

=

1 3

So, the required difference is

1 3

.