# Lesson 1

Problemas-historia y expresiones

### Lesson Purpose

The purpose of this lesson is for students to represent and solve Add To and Take From, Result Unknown story problems in a way that makes sense to them. They also write an expression to represent the action in a story problem.

### Lesson Narrative

Students solved these problem types and wrote matching expressions in kindergarten. In these problem types, the quantities can physically be joined or separated. This action leads to the resulting quantity. In this lesson students revisit these familiar problem types, and connect them to addition and subtraction expressions. When students connect expressions back to the story problem and explain the connection, they model with mathematics (MP4).

- Action and Expression

- MLR8

### Learning Goals

Teacher Facing

- Represent and solve Add To and Take From, Result Unknown problems in a way that makes sense to them.
- Write an expression to represent the action in a story problem.

### Student Facing

- Demos sentido a problemas-historia y resolvámoslos.

### Required Materials

Materials to Gather

### Required Preparation

### Lesson Timeline

Warm-up | 10 min |

Activity 1 | 20 min |

Activity 2 | 20 min |

Lesson Synthesis | 10 min |

Cool-down | 0 min |

### Teacher Reflection Questions

Reflect on the Advancing Student Thinking questions offered today. How did they support students in making sense of and solving story problems in a way that the students will be able to generalize?