Lesson 5

Choosing Strategies To Multiply

Est. Class Sessions: 2

Daily Practice and Problems

Teacher Notes
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TIMS Task

Refer students to the Multidigit Multiplication Strategies Menu in the Student Guide Reference section.

    1. at least 1950 bags of rice

    2. at least 78,000 pounds of rice

    3. Discuss the meaning of the term “at least.” It means that the actual numbers may be higher, but we don't know how much higher. So the calculations will give the minimum number of bags or pounds of rice. The actual numbers will not be lower. This is one of the times when an estimate is appropriate: when the exact number is difficult or impossible to determine.

    1. About 3850 miles

    2. Answers will vary; most likely the actual number of miles flown will not be the same as the answer because the question itself contains an estimate, “about” 275 miles per day.

R. Scientific Research

Solve the following problems using any method you choose except the calculator.

  1. Elias studies farming practices in India. He talked to 26 farmers. Each farmer harvested 75 bags of rice. Each bag holds at least 40 pounds of rice.
    1. The 26 farmers harvested how many bags of rice altogether?
    2. What is the least number of pounds of rice that the farmers harvested?
    3. What does “at least” mean in this problem? Is the actual amount of rice harvested by these farmers greater or less than your answer? Why?




  2. Julie studies bird migration. One day, Julie caught a sandhill crane and put a satellite transmitter device on it.
    1. If the crane flew about 275 miles per day after being released, how many miles did it fly during the next two weeks?
    2. Do you think the crane flew the exact number of miles in your answer? Why or why not?