Add and Subtract Like Fractions

Add and Subtract Like Fractions

What students learn

Students learn that like fractions already have the same denominator, so they can add or subtract the numerators while keeping the same-sized parts. Open with Adding Like Fractions: Same Denominator to see why the parts already match.

Why it matters

This idea keeps fraction work simple because the denominator does not change when the parts are equal. Adding Like Fractions: Combine the Numerators shows how the top numbers do the work.

Learn the idea

Subtraction works the same way when the pieces are equal-sized. Subtracting Like Fractions: Keep the Denominator shows that the denominator stays in place while the numerators change.

Try it

Have the student solve 2/8 + 3/8 and 7/10 - 2/10. After each answer, ask them to explain why the denominator stayed the same.

Parent guide

Keep the examples tied to equal parts of a whole. If the student gets stuck, point back to the denominator and ask what it tells them about the size of each part.