Lesson 12
Subtract Strategically
Lesson Purpose
The purpose of this lesson is for students to consider when they might use algorithms or other strategies to subtract.
Lesson Narrative
Students have learned several subtraction algorithms in prior lessons. Now students take time to consider when it makes sense to use an algorithm and when it makes sense to use another strategy, such as those learned in grade 2. Students will consider how thinking about the numbers in the problem can help them use their knowledge of subtraction to flexibly subtract within 1,000.
- Engagement
- MLR8
Learning Goals
Teacher Facing
- Subtract within 1,000 using algorithms or other strategies based on the numbers in the problem.
Student Facing
- Let’s consider when to use algorithms and when to use other strategies to subtract.
Required Materials
Required Preparation
Activity 2:
- Each group of 2 will need a paper clip.
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
Reflect on your experience with the Number Talks in the curriculum. What moves or questions have improved the learning for each of your students during this routine? What improvements would you make next time?
Suggested Centers
- How Close? (1–5), Stage 4: Add to 1,000 (Addressing)
- Number Puzzles: Addition and Subtraction (1–4), Stage 5: Within 1,000 (Addressing)
Print Formatted Materials
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| Student Task Statements | docx | |
| Lesson Cover Page | docx | |
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| Teacher Guide | Log In | |
| Teacher Presentation Materials | docx | |
| Blackline Masters | zip |