Lesson 3

Number Sentences

Est. Class Sessions: 2–3

Daily Practice and Problems

Teacher Notes
X

TIMS Task

  1. 54
  2. 17
  3. 53
  4. 6
  5. 11
  6. 15
  1. Answers will vary. A possible response: I first solved the left side: 80 − 40 = 40. Then I had to figure out what number would get me from 25 to 40; I skip counted by fives starting at 25: 30, 35, 40; n = 15.

J. What's Missing?

The letter n stands for a missing number. What number must n be to make each number sentence true?

  1. 30 + 24 = n
  2. n − 8 = 9
  3. n − 20 = 33
  4. 15 + n = 21
  5. 11 + n = 20 + 2
  6. 80 − 40 = 25 + n
  1. Show or tell how you solved Question F.