Lesson 5
Expanded Form of Numbers
Lesson Purpose
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
- Let’s represent three-digit numbers as a sum of the value of each digit.
Required Materials
Materials to Gather
Required Preparation
Activity 2:
- Each group of 2 needs 3 number cubes.
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)