Lesson 3

Kind of Bean

Est. Class Sessions: 3

Daily Practice and Problems

Teacher Notes
X

TIMS Bit

Students can describe and compare strategies for solving the problems “in their heads.”

  1. 12
  2. 22
  3. 82
  4. 2
  5. 92
  6. 82
  1. Possible response: Since 100 − 8 is 92, 100 − 18 will be ten less than that, or 82.

K. Mental Arithmetic

Solve these problems without paper and pencil. You may use a number line or mental math. Write down the answers. Explain how you found your answers.

  1. 7 + 5 =
  2. 7 + 15 =
  3. 7 + 75 =
  4. = 10 − 8
  5. = 100 − 8
  6. = 100 − 18
  1. Explain how solving Questions D and E can help you solve Question F.