Unit 7, Lesson 16
Subtract within 1,000
Grade 2
Preparation
Lesson Narrative
In previous lessons, students found differences, using various methods and representations, with an emphasis on strategies based on place value. They analyzed numbers to anticipate whether they may need to decompose one or more units to subtract.
In this lesson, students attend to the relationships between numbers in expressions to flexibly subtract. Although the focus of this section has been on interpreting and using methods based on place value, the number choices in this lesson also are intended to encourage the strategies students used in prior sections. Throughout this lesson, students explain their thinking and listen to and critique the reasoning of others (MP3).
- Engagement
None
- Explain (orally) strategies for subtracting within 1,000 based on place value or the properties of operations.
- Interpret (orally) subtraction strategies based on place value and the properties of operations.
- Let’s subtract in a way that makes sense.
Required Preparation
None
Teacher Reflection Questions
How are students using their understanding of number relationships and place value to choose their methods for subtracting? What more can be done to help students recognize and plan for the units they need to decompose when subtracting by place?