Lesson 2

Perimeter vs. Length Lab

Est. Class Sessions: 4

Daily Practice and Problems

Teacher Notes
X

TIMS Bit

Encourage students to use the counting-up and counting-back strategies to solve the problems.

  1. 4
  2. 397
  3. 9
  4. 7
  5. 104
  6. 105
  1. Strategies will vary. One possible strategy is to subtract 12 from 412 to get 400 and count back 3 more to get 397.

K. More Subtraction Practice

Use mental math to solve the following problems.

  1. 101 − 97 =
  2. 412 − 15 =
  3. 565 − 556 =
  4. 306 − 299 =
  5. 153 − 49 =
  6. 215 − 110 =
  1. Explain your strategy for solving Question B. What did you do “in your head”?