# Lesson 1

Comparemos longitudes

### Lesson Purpose

The purpose of this lesson is for students to compare the length of objects by lining up the endpoints and order objects by length.

### Lesson Narrative

In kindergarten, students compared the length of two objects directly by lining up the endpoints. They described the objects using language such as longer and shorter. In this unit the words “más largo que” // “longer than” and “más corto que” // “shorter than” are encouraged, although students may use “más alto que” // “taller than” in certain contexts related to height.

In this lesson, students compare the length of objects and consider how they know which is longer or shorter. Then, they order three objects by length.

The materials used in this lesson will be used again in the next lesson.

• Representation
• MLR2

### Learning Goals

Teacher Facing

• Compare the length of objects by lining up the endpoints.
• Order three objects by length and use language such as “shorter than” and “longer than” to describe the relationship between the lengths.

### Student Facing

• Comparemos y ordenemos objetos según su longitud.

### Required Preparation

Activity 1:

• Each group of 4 needs 10-12 objects to measure (thin classroom objects like pencils, crayons, paper clips, toothpicks, markers) including connecting cube towers of 3, 5, and 8.

Activity 2:

• Each group of 4 needs the collection of objects from the previous activity.

Activity 3:

• Gather materials from:
• Target Numbers, Stages 1–3
• Five in a Row, Stages 1–6
• Get Your Numbers in Order, Stage 1

Building On

Building Towards

### Lesson Timeline

 Warm-up 10 min Activity 1 15 min Activity 2 10 min Activity 3 15 min Lesson Synthesis 10 min Cool-down 0 min

### Teacher Reflection Questions

Reflect on how you can reinforce the work done in today's lesson outside of math class. When can you ask students to compare the length of objects around them?