Lesson 9

Comparemos números en la recta numérica

Lesson Purpose

The purpose of this lesson is for students to compare three-digit numbers using a number line.

Lesson Narrative

In previous lessons, students estimated the location of numbers on the number line within 100 and learned to locate numbers within 1,000 on the number line. In this lesson, students use the relative position of numbers on the number line to compare three-digit numbers. Students estimate the location of numbers on the number line and consider how the linear representation can help them compare numbers and explain their reasoning (MP3). Throughout the lesson, listen for the ways students make connections to place value as they estimate the location of numbers and compare numbers using the number line.

• Representation
• MLR8

Activity 1: Comparemos comparaciones

Learning Goals

Teacher Facing

• Compare three-digit numbers using the relative position of numbers on a number line.

Student Facing

• Comparemos números en la recta numérica.

Lesson Timeline

 Warm-up 10 min Activity 1 20 min Activity 2 15 min Lesson Synthesis 10 min Cool-down 5 min

Teacher Reflection Questions

Unlike talking, listening is a difficult thing to observe. At what points in the lesson did you observe students listening to one another’s ideas today in class? What indicators do you have that they were listening?

Suggested Centers

• Mystery Number (1–4), Stage 2: Three-digit Numbers (Addressing)
• Get Your Numbers in Order (1–5), Stage 1: Two-digit Numbers (Supporting)
• Jump the Line (2–5), Stage 1: Add and Subtract within 100 (Supporting)