# Lesson 15

Muchas frutas (optional)

### Lesson Purpose

### Lesson Narrative

This lesson is optional because it does not address any new mathematical content standards. This lesson does provide students with an opportunity to apply precursor skills of mathematical modeling. In previous lessons, students represented and solved Put Together/Take Apart, Both Addends Unknown story problems. This lesson builds on students’ experience in the Math Stories center.

In this lesson, students use familiar contexts to generate and solve Put Together/Take Apart, Both Addends Unknown story problems. In the second activity, students are encouraged to find all possible solutions and use reasoning based on patterns explored in previous lessons (MP8).

When students attend to the mathematical features of a situation, adhere to mathematical constraints, make choices, and translate a mathematical answer back into the context they model with mathematics (MP4).

- Action and Expression

- MLR8

### Learning Goals

Teacher Facing

- Solve addition and subtraction story problems.

### Student Facing

- Inventemos problemas-historia y resolvámoslos.

### Required Materials

### Required Preparation

Activity 1:

- Each group of 2 needs 1 connecting cube.

Activity 2:

- Each group of 2 needs at least 10 two-color counters.

### Lesson Timeline

Warm-up | 10 min |

Activity 1 | 20 min |

Activity 2 | 20 min |

Lesson Synthesis | 10 min |