# Lesson 15

Write Equations for Story Problems

### Lesson Purpose

The purpose of this lesson is for students to solve story problems with unknowns in all positions using addition and subtraction. Students write equations to represent each story problem.

### Lesson Narrative

In the previous lesson, students matched story problems to equations.

In this lesson, students work in pairs to solve four different types of story problems and show their thinking using drawings, numbers, words, or equations. Students create visual representations of their thinking for one story problem and participate in a gallery walk in which they write equations to match other's representations and show how they made sense of each other's work. Throughout the lesson, students make connections between story problems, representations, and equations (MP2).

Prior to this lesson, the teacher may consider reading Sadako and the Thousand Paper Cranes, by Eleanor Coer.

• Action and Expression

### Learning Goals

Teacher Facing

• Use addition and subtraction to solve story problems with unknowns in all positions.
• Write equations to represent story problems.

### Student Facing

• Let’s solve story problems and write equations.

### Required Materials

Materials to Gather

### Lesson Timeline

 Warm-up 10 min Activity 1 10 min Activity 2 25 min Lesson Synthesis 10 min Cool-down 5 min

### Teacher Reflection Questions

In this lesson, students made connections between story problems and different representations of their thinking, including equations. What questions did you ask to help make their connections more visible? What did these connections reveal about students’ understanding of different story problem types?