Subtracting Fractions with Common Denominators

Subtracting fractions with common denominators can be made simple. Just tell your students to follow the two steps below. We’ve also included some powerpoint and PDF files with examples in English and Spanish. If you come to this site often, you know we LOVE examples for teaching math.

3 simple steps to subtracting fractions with common denominators

1. Make sure the bottom numbers (the denominators) are the same. That is, make sure you really do have a common denominator.
2. Subtract the top numbers (the numerators).
3. Put the answer over the same denominator.

That’s it. You’re done!

Here is the question to pose to your students:

You own a candy store. You have containers of candy divided into eighths. You start the day with 28/8 containers of candy. You sell 4/8 containers. How many containers do you have left?

PDF	POWERPOINT
An example of subtracting fraction with like denominators   IN SPANISH: Un ejemplo de resta de fracciones utilizando común denominador	Subtraction fractions with like denominators   IN SPANISH: Un ejemplo de resta de fracciones utilizando común denominador

If you want to get fancier, you can reduce the fraction to lowest terms, but that’s not required for this lesson. If that IS your next step, check out this lesson plan on equivalent fractions.