Lesson 3

The Meaning of the Mean

Est. Class Sessions: 2–3

Daily Practice and Problems

Teacher Notes
X

TIMS Bit

  1. D. 30
  2. Possible response: 18 is two less than 20, so 18 × 15 is 2 × 15 or 30 less than 20 × 15. 20 × 15 = 300, so 18 × 15 = 300 − 30 = 270.
  3. C. 86
  4. Possible response:
    100 × 43 = 4300
    2 × 43 = 86
    4300 + 86 = 4386

I. Multiple Choice

  1. How much less is 18 × 15 than 20 × 15? Fill in the circle next to the correct answer.
    1. 2
    2. 15
    3. 18
    4. 30
    5. 45
  2. Show or tell how you can use the answer to Question 1 to solve 18 × 15.
  3. How much more is 102 × 43 than 100 × 43? Fill in the circle next to the correct answer.
    1. 2
    2. 4
    3. 86
    4. 102
    5. 204
  4. Show or tell how you can use the answer to Question 3 to solve 102 × 43.