Lesson 16
Round Numbers
Lesson Purpose
The purpose of this lesson is for students to round multi-digit whole numbers within 1,000,000 to the nearest 1,000, 10,000, and 100,000.
Lesson Narrative
In grade 3, students rounded whole numbers to the nearest 10 and 100. In previous lessons, they worked to find the closest multiples of powers of 10. Here, students build on this work to round whole numbers to the nearest 1,000, 10,000, and 100,000. Students revisit the convention of rounding up when a number is exactly halfway between two consecutive multiples of a power of 10.
- Action and Expression
- MLR8
Activity 1: Round to What?
Learning Goals
Teacher Facing
- Round multi-digit whole numbers to the nearest 1,000, 10,000, and 100,000.
Student Facing
- Let’s round some large numbers.
Required Preparation
CCSS Standards
Addressing
Lesson Timeline
| Warm-up | 10 min |
| Activity 1 | 20 min |
| Activity 2 | 15 min |
| Activity 3 | 20 min |
| Lesson Synthesis | 10 min |
| Cool-down | 5 min |
Teacher Reflection Questions
How readily did students transition from reasoning about nearest multiples using number lines to reasoning numerically and rounding? What progress have you seen them make in using representations flexibly to support their thinking? What did students say or do that showed this progress?
Suggested Centers
- Mystery Number (1–4), Stage 5: Six-digit Numbers (Addressing)
- Tic Tac Round (3–5), Stage 1: Nearest Ten or Hundred (Supporting)