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Irma said, “I can draw a rectangle to show the problem, too.”
- What is another way to multiply 20 30?
Nila and Alexis tried their methods on the same problem.
- Explain how Alexis used the turn-around rule. How did she change the order of the factors?
- Use Irma's rectangle method to multiply 40 60. Draw the rectangle.
- Use Nila's or Alexis's method to multiply 30 90. Write the number sentences.
- Use any method you choose to multiply 70 50.
- Which method is the most efficient: Irma's, Nila's, Alexis's, or a different method? Explain why you think so.