If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Adding and subtracting fractions with unlike denominators

6 videos
4 skills
We've already had some good practice adding fractions with like denominators. We'll now add fractions with unlike denominators. This is a very big deal. After this tutorial, you'll be able to add, pretty much, any two (or three or four or... ) fractions!

Adding fractions with unlike denominators: units of 10

VIDEO 4:25 minutes
A great way to learn how to add fractions with unlike demoninators is to do so with denominators in units of 10 and 100. Like this...

Adding fractions with 10 and 100 as denominators

PRACTICE PROBLEMS

VIDEO 9:50 minutes
How to add and subtract fractions.

VIDEO 4:06 minutes
To solve this problem, we need to find the least common multiple to get at the common denominator. Can you help? We bet you can!

VIDEO 2:33 minutes
To add these fractions we need to find a common denominator. The answer can be expressed as a mixed number. Let's try together.

PRACTICE PROBLEMS

Subtracting fractions: different denominators

VIDEO 4:24 minutes
If you conquered adding fractions with different denominators, then subtracting fractions will be a snap. Don't worry...we'll take it slow and explain every step.

Subtracting fractions with unlike denominators

PRACTICE PROBLEMS