How do you add and subtract fractions with like denominators?
When adding or subtracting like fractions (fractions that have the same denominator), add or subtract the numerators only and keep the same denominator.
Example 1: |
To add fractions with like denominators: |
A food vendor has 
of a tray of pink cotton candy and 
of a tray of blue cotton candy.
Since the fractions have the same denominators, add the numerators 3 and 4, and write 7 as the numerator of the sum.
The sum will have the same denominator because you are finding how many ninths of a whole tray is filled with cotton candy. So, 9 is the denominator of the sum.
The food vendor has of a tray of 
pink and blue cotton candy. This sum is in simplest form because the numerator and denominator have no common factor other than 1.
