Lesson 2

In Twos, Threes, and More

Est. Class Sessions: 3

Daily Practice and Problems

Teacher Notes
X

TIMS Bit

Use this bit to review the facts in Group 3. Ask students to describe strategies. Children are often comfortable with sums of 10 (e.g., 2 + 8, 6 + 4). They can use these facts to find differences from 10 (10 − 8 = 2, 10 − 4 = 6) or to find similar facts such as 11 − 4.

  1. 2
  2. 3
  3. 4
  4. 6
  5. 7
  6. 5
  7. 4
  8. 5
  9. 6
  10. 7
K−M.
Discuss the strategies students used. Look for counting back, counting up, and using tens.

C. Subtraction: Making Tens

Write the answers to these problems.

  1. 10 − 8 =
  2. = 11 − 8
  3. = 9 − 5
  4. 10 − 4 =
  5. 11 − 4 =
  6. = 9 − 4
  7. = 10 − 6
  8. 11 − 6 =
  9. 11 − 5 =
  10. 12 − 5 =
  1. Show or tell how you solved Question H.
  2. Does knowing the answer to 11 − 6 help you solve 11 − 5? If so, how?
  3. Solve Question J using one of your classmates' strategies. Be ready to share with the class.