This lesson focuses on 5.NF.A.1 and 5.NF.A.2: Adding and subtracting fractions with unlike denominators. Students use models and equations to solve addition and subtraction word problems. Core Action 3 is strongly illustrated by this lesson.
Adding and Subtracting Fractions with Unlike Denominators (Tinker)Download
In this part of the lesson. the teacher provides her students with the opportunity to work through a math problem involving subtracting fractions with different denominators. The students know who their partners are, and they take turns teaching each other how to solve the math problem. The teacher also has the students choose how they will solve their problem.
Here, the students are working through an addition problem in which they are adding two fractions with different denominators. The students are not only working through the problem, but they also have experiences in which they have to explain their thinking with each other.
Here, the teacher has her students pause in their partner work to check in with them and not only check for understanding but to also reinforce a particular strategy for them to use when solving their problems. The teacher models the fractions and the common denominator on the board so students can visualize the mathematics. The also reinforces the use of mathematical language over the use of informal language.
In this part of the lesson, the teacher selects three different students to share their solutions to a math problem on the board. The students then discuss the different solutions and critique the reasoning of their classmates. This method not only shows students a variety of methods to solve problems but also provides the opportunity for students to see errors in their thinking next to correct solutions.