This lesson focuses on the conceptual understanding aspect of 5.NF.A.2--using visual fraction models to add two fractions with unlike denominators. Building this conceptual understanding of using equivalence to add unlike denominators is an important precursor to using addition or subtraction to solve word problems with these types of fractions. This lesson includes strong examples of indicators from all three Core Actions.
Adding Fractions with Unlike Denominators--Day 1 of 2 (Zafrin)Download
Students are prompted to solve a given equation as the lesson is launched. The teacher notes that this equation is an example of learning from the prior grade that students will build on in the day's lesson.
A pair of students checks back in with the teacher to demonstrate their understanding. Rather than simply praising the boys for their correct thinking, the teacher poses probing questions to encourage them to explain and further develop their understanding.
As students explain their thinking, the teacher uses virtual manipulatives to model what the students are saying in order to make the explanations clear to the rest of the group. After some exploration time, the teacher brings the whole class together and asks students to share their developing thinking. The students who share are comfortable explaining their thinking with the
group, and they elaborate as needed.
In this part of the lesson, students work with a partner to complete grade-level appropriate tasks throughout the lesson. The teacher monitors the class, checking in with students as needed. The lesson is designed to allow students to explore new content with peers before whole group instruction of the content. The teacher asks guiding questions and promotes the use of manipulatives to support students as they struggle and persevere to develop their understanding.
The teacher checks in with partners as they explore, asking guiding questions and clarifying as needed. After some time has passed, the teacher pulls a small group of students aside for more explicit small-group instruction.
As students explain their thinking, the teacher asks guiding questions to help develop students' precision in language. She gives students opportunities to restate their thinking to reinforce this precise mathematical language, and students are able to restate and re-voice appropriately.