Lesson 5

Break-Apart Products

Est. Class Sessions: 2

Developing the Lesson

Part 2. Exploring Larger Break-Apart Products

Ask students to work in pairs to solve Question 6 on the Exploring Break-Apart Products pages in the Student Activity Book. Display Questions 6 and 7 for the class. As students work, encourage them to look for ways to break the rectangles apart so that both the multiplication and addition are easy to do. Sample responses are shown in Figure 2.

For example, ask student pairs:

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  • Why did you choose to divide the 4 into 2 and 2? (Possible response: Because doubles are easy. 2 × 12 = 24 and I can double 24 to make 48.)
  • Is there a way to divide 12 so that both the multiplication and addition are easy to do in your head? (Possible response: 12 = 10 + 2. I know that 4 × 10 = 40 and 4 × 2 = 8. Adding 40 + 8 is easy, too.)

Discuss students' strategies for Question 6 with the class. Then, ask students to complete the remaining problems with their partners (Questions 8–9).

Student Guide:
Student Activity Book: 56 57
Answers
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Master:
Sample student solutions for Questions 6A and 6B on the More Break-Apart Products page
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