# Lesson 7

Solve Both Addends Unknown Story Problems

### Lesson Purpose

### Lesson Narrative

In the previous lesson, students represented a questionless Put Together/Take Apart, Both Addends Unknown story problem. In this lesson, students notice and discuss that Put Together/Take Apart, Both Addends Unknown story problems have more than 1 solution. In the second activity, students discuss how labels show the solution to the story problem.

In a previous section, students used expressions to represent compositions and decompositions of numbers. Beginning in the second activity and throughout the rest of the section, students write an expression to record the solution or solutions they find for the story problem.

Throughout this section, the teacher records student responses with equations. Equations are read aloud to students as “10 is 5 plus 5.” Students will be asked to interpret and work with equations in the next section.

- Action and Expression

- MLR8

### Learning Goals

Teacher Facing

- Solve Put Together/Take Apart, Both Addends Unknown story problems.

### Student Facing

- Let’s solve story problems.

### Required Materials

Materials to Gather

Materials to Copy

- Math Stories Stage 3 Pictures
- Math Stories Stage 3 Recording Sheet

### Required Preparation

Activity 3:

- Gather materials from:
- What’s Behind My Back, Stage 1
- 5-frames, Stages 1 and 2
- Make or Break Apart Numbers, Stage 1

### Lesson Timeline

Warm-up | 10 min |

Activity 1 | 10 min |

Activity 2 | 10 min |

Activity 3 | 25 min |

Lesson Synthesis | 5 min |

Cool-down | 0 min |