What you need to know

Things to remember:

  • If we add or subtract two fractions with the same denominator, we can just add or subtract the top numbers.
  • If we add or subtract two fractions with the same denominator, the denominator in the answer will be the same as the denominator in the question.

Let’s recap a little, below we have a fraction of a grid shaded in and what this means in terms of numbers.

=\frac{3}{6}

 

 

Here, the numerator is 3, and the denominator is 6.

If two fractions have the same denominator, we can actually just add them straight away

\frac{3}{6} + \frac{2}{6}= \frac{5}{6}

 

 

Because our two fractions have been split into the same amount, so is the answer, so the denominators stay the same! We have added 3 sixths and 2 sixths, to give us a total of 5 sixths. We can do the same with subtraction.

\frac{3}{6} - \frac{2}{6}= \frac{1}{6}

 

Example Questions

Question 1: Find the answer to:
\frac{3}{8} + \frac{1}{8}

Answer

\frac{3}{8} + \frac{1}{8}=\frac{4}{8}

 

 

So, the answer is \frac{4}{8}

Question 2: Find the answer to:
\frac{7}{9} - \frac{5}{9}

Answer

\frac{7}{9} - \frac{5}{9}=\frac{2}{9}

 

 

So, the answer is \frac{2}{9}