Lesson 13

The purpose of this lesson is for students to make connections between different representations of situations for sums and differences.

In previous lessons, students were introduced to the number line. They learned that numbers are located at points on the line, depending on their distance from zero. They represented addition and subtraction equations with unknowns in all positions on number lines. Students have also used tape diagrams to represent story problems in previous lessons.

In this lesson, students interpret multiple representations and match them to story problems. In the first activity students are not asked to solve the problems. This allows them to focus on how each problem can be represented in different ways, rather than finding the solution. In the second activity, students are given diagrams to complete, but they can find the solution in any way that makes sense to them. They are also given the option to use a number line if it helps.

• Create a set of cards from the blackline master for each group of 3.

Which students came up with an unexpected strategy or connection in today’s lesson? What are some ways you can be more open to the ideas of each and every student?