Lesson 3

Multiplication Models and Strategies

Est. Class Sessions: 2

Daily Practice and Problems

Teacher Notes
X

TIMS Task

Answers will vary. Encourage efficient mental estimation strategies.

    1. 276 and 149
    2. 57 and 39
    3. 149 and 57 or 149 and 39
    4. Possible response: I choose 149 and 57 because 149 is close to 150 and 57 is close to 60 so when you add them the answer will be around 210 and that is close to 200.
  2. 149; Possible response: If you double 149 it will be close to 300 because 149 is close to 150 and when you double 150 it is 300.

H. Which Two Add Up?

Do not use paper and pencil to solve these problems.

        39         276         149         57

  1. Which two of these numbers should you add if you want an answer:
    1. over 400? ______________________________
    2. less than 100? ______________________________
    3. close to 200? ______________________________
    4. Show or tell how you solved Question 1C.
  2. When doubled, which number will be close to 300? Show or tell how you decided.