Lesson 4

Which Picks Up More?

Est. Class Sessions: 4–5

Daily Practice and Problems

Teacher Notes
X

TIMS Bit

This bit reviews the facts in Group 8. They can be solved by “thinking addition” using doubles, although other strategies would also be useful. Let students tell the class how they found the answers. Discuss which strategies are most efficient.

  1. 8
  2. 9
  3. 7
  4. 9
  5. 8
  6. 8
  7. 4
  8. 3
  9. 30
  1. Possible strategy: Students may use the addition double 9 + 9.

K. Subtraction: Using Doubles Again

Do these problems in your head. Write only the answers.

  1. 16 − 8 =
  2. 17 − 8 =
  3. 15 − 8 =
  4. 18 − 9 =
  5. 18 − 10 =
  6. 15 − 7 =
  7. 8 − 4 =
  8. 7 − 4 =
  9. 60 − 30 =
  1. Explain your strategy for solving Question D.