Unit 4, Lesson 11
Multiplication Strategies on Ungridded Rectangles
Grade 3
Preparation
Lesson Narrative
Previously, students used gridded rectangles to represent strategies based on the distributive and associative properties. Here, they use the same strategies, but represent them on an area diagram without a grid. Then students match expressions that could represent the area of the same rectangle, without using diagrams. The reasoning helps students work toward fluent multiplication within 100.
- Engagement
- MLR2
- Label ungridded rectangles and explain (orally) strategies based on properties of operations for calculating the area of each rectangle.
- Match (orally) expressions that represent the area of the same rectangle, including those that show the associative and distributive properties.
- Let’s use different strategies to find the area of ungridded rectangles.
Required Preparation
- Create a set of cards from the blackline master for each group of 2 or 4.
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?