Unit 7, Lesson 13
Decompose Tens or Hundreds
Grade 2
Preparation
Lesson Narrative
In a previous lesson, students subtracted from a three-digit number, using place-value strategies that included decomposing a ten.
In this lesson, students interpret representations of subtraction that show decomposing a ten and a hundred. They use base-ten blocks and their understanding of place value to explain why the method works (MP7). Students may continue to use the base-ten blocks—or any representation that makes sense to them—to subtract within 1,000.
- Action and Expression
- MLR5
- Interpret (orally) base-ten diagrams that represent subtraction strategies based on place value.
- Use place-value strategies to subtract within 1,000 when a ten or a hundred is decomposed, and explain (orally) the strategy.
- Let’s decompose a ten or a hundred to subtract.
Required Preparation
None
Teacher Reflection Questions
Which students came up with an unexpected strategy in today’s lesson? What are some ways you can be more open to the ideas of each and every student?