Number & Operations for Teachers 

Copyright David & Cynthia Thomas, 2009

Exercises

1. Model the following operations using the indicated concept models. In each case, use the model to demonstrate that multiplication is repeated addition.

a. 3 x 5 (set model)

b. 4 x 7 (number line)

c. 5 x 12 (rectangular array)

2. Using the rectangular array model, expanded notation, and standard notation, find the following products. Make explicit the connections between the model and both notations.

a. 15 x 24

b. 13 x 14

3. Model the following operations using the indicated concept models. In each case, use the model to demonstrate that division is repeated subtraction.

a. 12 ¸ 3 (measurement model)

b. 15 ¸ 3 (partitive model)

4. To model the following division problems, would you use a measurement or partitive approach? Why?

a. 50 ¸ 2

b. 50 ¸ 25

5. Complete the following figure and write a question illustrating each of the six indicated connections

1. Complete the following figure and write a question illustrating each of the six indicated connections