# Lesson 8

Ecuaciones en una recta numérica

### Lesson Purpose

The purpose of this lesson is for students to write equations based on number lines and represent equations on the number line.

### Lesson Narrative

In the previous lesson, students interpreted representations of addition and subtraction equations on the number line. They used the direction of the arrow to determine what operation was represented and matched equations to number lines.

In this lesson, students write equations based on number line representations and represent given equations on number lines.

- Representation

- MLR8

Activity 1: Representemos ecuaciones

### Learning Goals

Teacher Facing

- Use number line diagrams to represent and write addition and subtraction equations.

### Student Facing

- Escribamos ecuaciones y representémoslas en una recta numérica.

### Required Preparation

### Lesson Timeline

Warm-up | 10 min |

Activity 1 | 15 min |

Activity 2 | 20 min |

Lesson Synthesis | 10 min |

Cool-down | 5 min |

### Teacher Reflection Questions

What evidence have students given that they understand the connection between the number line and written equations? What questions did you ask to make the connection more visible?

### Suggested Centers

- Number Puzzles: Addition and Subtraction (1–4), Stage 4: Within 100 with Composing (Addressing)
- Number Line Scoot (2–3), Stage 1: Twos, Fives, and Tens (Addressing)