Lesson 17
Apply Rounding
Lesson Purpose
The purpose of this lesson is for students to use rounding to learn about situations and solve problems involving multi-digit whole numbers within 1 million.
Lesson Narrative
Previously, students extended their knowledge of rounding to the nearest 1,000, 10,000, and 100,000. They began to generalize strategies for rounding any number within 1,000,000 to any place. In this lesson, students practice rounding such numbers and interpret the rounded numbers in context in order to solve problems. In doing so, they practice reasoning quantitatively and abstractly (MP2). Students also learn the benefits and limitations of rounding numbers when solving problems.
- Engagement
- MLR7
Learning Goals
Teacher Facing
- Describe how rounding can help or hinder problem-solving.
- Round multi-digit whole numbers within 1,000,000 to solve problems.
Student Facing
- Let’s round large numbers to learn about situations and solve problems.
Required Preparation
Lesson Timeline
| Warm-up | 10 min |
| Activity 1 | 20 min |
| Activity 2 | 15 min |
| Activity 3 | 15 min |
| Lesson Synthesis | 10 min |
| Cool-down | 5 min |
Teacher Reflection Questions
What surprised you about students’ thinking in today’s activities? What reasoning strategies did you anticipate? What did you not anticipate?
Suggested Centers
- Mystery Number (1–4), Stage 5: Six-digit Numbers (Addressing)
- Tic Tac Round (3–5), Stage 1: Nearest Ten or Hundred (Supporting)