# Lesson 5

### Lesson Purpose

The purpose of this lesson is for students to use expanded form and base-ten numerals to represent numbers within 1,000.

### Lesson Narrative

In previous lessons, students represented three-digit numbers by recording how many of each unit (for example, 357 as 3 hundreds, 5 tens, 7 ones). They also connected representations of a number using the fewest number of base-ten blocks to the value of the digits in three-digit numbers.

In this lesson, students extend their understanding of ways to express the value of the digits in three-digit numbers to include expanded form. They represent three-digit numbers as the sum of the value of each digit (for example, $$357 = 300 + 50 + 7$$).

• Action and Expression
• MLR8

### Learning Goals

Teacher Facing

• Read, write, and represent three-digit numbers using base-ten numerals and expanded form.

### Student Facing

• Representemos números de tres dígitos como la suma del valor de cada dígito.

### Required Materials

Materials to Gather

### Required Preparation

Activity 2:

• Each group of 2 needs 3 number cubes.

Building Towards

### 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

As students represented numbers in expanded form and as three-digit numbers, what evidence did you see that they understand place value?

### Suggested Centers

• Greatest of Them All (1–5), Stage 1: Two-digit Numbers (Supporting)
• Mystery Number (1–4), Stage 1: Two-digit Numbers (Supporting)