Add and Subtract Fractions with Related Denominators

To add (or subtract) unlike fractions, first change them to fractions with same denominator. Then, add (or subtract) the numerators and put the result over the common denominator.

 

For example: Let’s add the fractions
1 2
and
1 4
.

Notice that the denominators of both the fractions are not the same.

 

So, let’s change them to fractions with same denominator.

 

Find the equivalent fraction of
1 2
having denominator 4.
 
1
2
=
1 × 2
2 × 2
=
2
4

 


Now, add the fractions. Add the numerators and put the obtained result over the common denominator.

 

 

1
2
+
1
4
=
2
4
+
1
4
                 =
2 + 1
4
                 =
3
4

 

 

So,
1
2
+
1
4
=
3
4
.