# Lesson 3

Escojamos objetos para comparar su longitud indirectamente

### Lesson Purpose

The purpose of this lesson is for students to compare the length of two objects that cannot be compared directly.

### Lesson Narrative

In the previous lesson, students used a string to compare two lengths indirectly.

In this lesson, students choose their own object to compare the length of two other objects indirectly. Throughout the lesson, students make their own choices about what objects to use and how to use them to compare two other objects (MP5). Students also have opportunities to see and compare the different choices that their peers make. These conversations help prepare students for iterating same-sized length units to measure length in future lessons.

• Engagement
• MLR8

### Learning Goals

Teacher Facing

• Choose and use objects to compare lengths of other objects indirectly.

### Student Facing

• Comparemos la longitud de objetos que no se pueden mover.

### Required Preparation

Activity 1:

• Each group of 2 needs:
• Connecting cubes in singles and towers of 10
• 6-inch and 10-inch piece of string
• Unsharpened pencil
• Scissors

Activity 2:

• Each group needs measuring materials from the previous activity.

### Lesson Timeline

 Warm-up 10 min Activity 1 15 min Activity 2 25 min Lesson Synthesis 10 min Cool-down 0 min

### Teacher Reflection Questions

How does indirect comparison prepare students to measure length by iterating length units in future lessons?