Add Fractions with Unlike Denominators

Add Fractions with Unlike Denominators

What students learn

Students learn to add fractions that do not start with the same denominator. Begin with Add Fractions: Start by Finding a Common Denominator so the need for shared pieces is clear right away.

Why it matters

This is the move that makes fraction addition work in real problems. Once students know how to line up the pieces, they can solve recipe problems, measurement problems, and number puzzles more confidently. Add Fractions: Find the Least Common Multiple shows one clean path to the shared denominator.

Learn the idea

Students should hear the routine in the same order every time: find a common denominator, rewrite the fractions, add the numerators, and simplify if needed. Add Fractions: Rewrite the Fractions and Combine the Numerators shows that middle step clearly, and Add Fractions: Check the Answer at the End closes the example by checking the final sum.

Try it

Ask the student to solve 1/2 + 1/3, 2/5 + 1/4, and 3/4 + 1/5. Have them say the shared denominator out loud before they rewrite anything. If the answer feels too big or too small, ask them to compare it with each addend and explain why.

Parent guide

Keep the work slow and visible. Encourage the child to write each rewritten fraction before adding the numerators. If they try to add denominators, pause and point back to the model in the lesson. The goal is to build the habit, not rush the answer.