LESSON 5 Break-Apart Products

Mrs. Dewey's class was working on multiplication problems. “One way to solve a multiplication problem is to break it into smaller problems that are easier to solve,” said Mrs. Dewey. “Does anyone use that method?”

“I use the break-apart method to help me with multiplication facts that are hard for me to remember,” said Grace. “Here is an example: To solve 6 8, I break the 8 into 5 + 3. I know 6 5 is 30 and 6 3 is 18. I add them together to get 6 8 = 48. Here is a picture.”

Check-In: Questions 1–5

Look at the rectangle and the number sentences above. Answer the questions to connect the picture with the number sentences.

What does the 6 represent?
What does the 8 represent?
What does each number in the number sentence 6 5 = 30 represent?
What does each number in the number sentence 6 3 = 18 represent?
How did Grace find the total number of squares in the large rectangle?
Why do you think Grace decided to break 8 into 5 + 3?

Work with a partner. Find a different way to break 6 8 into parts. Make a sketch to show how you break the rectangle into parts. Write number sentences that match your rectangles. Follow the example above.