Lesson 7

Multiplication Strategies for Larger Numbers

Est. Class Sessions: 2

Daily Practice and Problems

Teacher Notes
X

TIMS Bit

Refer students to the Multiplication Strategies Menu in the Student Guide Reference section.

Discuss possible mental math strategies. For example, students may use the doubling and halving strategy for Question 1B. Double 5 is 10. 10 × 622 is 6220. Half of 6220 is 3110.

    1. 4275
    2. 3110
    3. 5114
  2. Strategies may vary. Students may multiply 475 × 10 to get 4750. Or, students may round 475 to 500 and multiply by 9; 9 × 500 is 4500.

W. More Multiplication Practice

Use paper and pencil or mental math to solve the following problems. Estimate to be sure your answers are reasonable.

    1. 475 × 9
    2. 622 × 5
    3. 643 × 8
  1. Show or tell your estimation strategy for Question 1A.