Grade 6 · Unit 1Topic 2 of 4~14 min

Adding & Subtracting Fractions

Same bottom number? Add the tops. Different? Find a common denominator first.

Step 1 · Learn

Walkthrough

Read this first — it covers the idea in plain language with a worked example.

Same denominator

When the bottom numbers (denominators) already match, just add or subtract the top numbers (numerators) and keep the denominator the same. For example, 2/7 + 3/7 = 5/7.

Different denominators

When the bottoms are different, you first rewrite both fractions with a common denominator — usually the LCM of the two denominators.

Find a common denominator (the LCM of the bottom numbers).
Rewrite each fraction with that denominator.
Add or subtract the numerators; keep the denominator.
Simplify the answer if you can.

Worked example

1/3 + 1/4

A common denominator is 12.
1/3 = 4/12 and 1/4 = 3/12.
4/12 + 3/12 = 7/12.

Watch out

Never add the denominators. 1/2 + 1/2 = 1, not 2/4.

Step 2 · Watch

Video walkthrough

Watch the main video, then check the second take if you want another explanation.

Math Antics

Adding & Subtracting Fractions

Find common denominators, then add or subtract.

Watch on YouTube

Virtual Nerd

Adding Fractions (another take)

Same and different denominators, side by side.

Watch on YouTube

Step 3 · Practice

Practice

Try a worksheet or work through some problems before the quiz.

Math Worksheets 4 Kids

Fractions practice

Open resource

Step 4 · Check

Quick check

A couple of questions to make sure this topic stuck. Retake as many times as you want.

Adding & Subtracting Fractions

Question 1 of 3

Easy

What is 2/7 + 3/7?

Previous · Topic 1 of 4Factors, Multiples, GCF & LCM Next up · Topic 3 of 4Multiplying & Dividing Fractions