Lesson 8

Workshop: Subtraction Practice

Est. Class Sessions: 2

Daily Practice and Problems

Teacher Notes
X
  1. Possible responses: Agree; 27 is close to 30 and 60 − 30 = 30, so
    60 − 27 is about 30.
  2. Possible response: 60; 79 is close to 80 and 22 is close to 20.
    80 − 20 = 60, so 79 − 22 is about 60.

BB. Subtraction with Friendly Numbers

  1. Julie said 60 − 27 is about 30. Do you agree? Tell why or why not.
  2. Find an estimate for 79 − 22. Show or tell your thinking.