Introduction to Adding and Subtracting Fractions with Different Denominators

What you’ll learn to do: Add and subtract fractions with different denominators

Two pieces of coffee cake with crumb topping on a green plate

Does Maria have enough sugar to make her favorite coffee cake?

Have you ever needed to add or subtract fractions with different denominators? One place this often comes up is in the kitchen. For example, Maria’s coffee cake recipe calls for 2/3 cup of sugar in the cake, and 1/4 cup of sugar in the crumb topping. Maria notices she’s getting low on sugar, so she wants to make sure she has enough before she starts mixing the batter. How much sugar does she need in all? To figure it out, Maria needs to add fractions with different denominators. In this section, you’ll learn how to find the least common denominator and convert fractions in order to add and subtract.

Before you get started, take this readiness quiz.

readiness quiz

1)

Find two fractions equivalent to [latex]{\Large\frac{5}{6}}[/latex]

If you missed this problem, review the following video.

2)

If you missed this problem, review the following video.