Subtract Fractions with Unlike Denominators

Subtract Fractions with Unlike Denominators

What students learn

Students learn to subtract fractions that do not begin with the same denominator. Open with Subtract Fractions: Start by Finding a Common Denominator so the strategy begins with a clear visual reason.

Why it matters

Subtraction with fractions is the same careful thinking as addition: the pieces must match before the numbers can be compared or removed. Subtract Fractions: Find the Least Common Multiple shows how the shared denominator is chosen.

Learn the idea

After the denominator is shared, the fractions are rewritten and the numerators are subtracted. Subtract Fractions: Rewrite the Fractions and Subtract the Numerators shows the subtraction step in order, and Subtract Fractions: Check the Final Difference gives the finished answer and a final reasonableness check.

Try it

Have the student solve 3/4 - 1/6, 5/8 - 1/4, and 7/10 - 2/5. Ask them to explain why the denominators must match before the subtraction can happen. If they are unsure, have them redraw the fractions with shaded models.

Parent guide

Stay close to the visual model. Ask your child to name the shared denominator, then the rewritten fractions, then the subtraction. If they skip a step, bring them back to the lesson video and let them point to the part that matches their work.