Lesson 20
Add and Subtract Within 1,000,000
Lesson Purpose
The purpose of this lesson is for students to add and subtract within 1,000,000 with multiple compositions or decompositions.
Lesson Narrative
In this lesson, students use the standard algorithm for addition and subtraction to the hundred-thousands place. They build their fluency with the algorithm as they encounter examples where more than one digit has to be decomposed in order to subtract. Students also look at errors that are commonly made when using the algorithm to find sums and differences.
- Action and Expression
- MLR8
Activity 1: Add and Subtract Large Numbers
Learning Goals
Teacher Facing
- Add and subtract multi-digit numbers, with multiple compositions or decompositions, using the standard algorithm.
Student Facing
Let’s use the standard algorithm to add and subtract.
Required Materials
Materials to Gather
Required Preparation
CCSS Standards
Addressing
Lesson Timeline
| Warm-up | 10 min |
| Activity 1 | 15 min |
| Activity 2 | 20 min |
| Lesson Synthesis | 10 min |
| Cool-down | 5 min |
Teacher Reflection Questions
What connections did students make between the decomposition of base-ten units using expanded form and using the standard algorithm when subtracting large numbers?
Suggested Centers
- Tic Tac Round (3–5), Stage 2: Any Place (Addressing)
- Number Puzzles: Addition and Subtraction (1–4), Stage 6: Beyond 1,000 (Addressing)