Children Solving Multiplication Word Problems

1.  Consider the following problem:

Sara has 5 boxes of toy turtles. There are 7 turtles in each box. How many turtles does Sara have?

A.  If a child were to use blocks to solve this problem, what you think you would see? Explain why you think this.

Sara, a second grader, solved this problem as follows:

“Take 2 from each 7 and that would be 5 in each box. So 5, 10, 15, 20, 25, there would be 25 turtles. But we have 2 more still for each box. Five 2’s would be 10. Ten plus 25 is 35.

B.  Sara clearly knows how to count by 5’s. Why do you think she solved it the way she did rather than just counting 5, 10, 15, 20, 25, 30, 35?

C.  In order to solve this problem, Sara separated the problem into two separate problems. What two problems did she ended up solving

D.  Use a strategy similar to Sara’s to solve the problem if there were 4 boxes with 6 in each box.

2.  Consider the following problem:

Jason has 12 bags of cookies. Each bag has 6 cookies in it. How many cookies does Jason have all together?

A.  If a child were to use blocks to solve this problem, what do you think you would see?

Abigail, a second grader, solved the problem as follows:

“If there were 10 bags, there would be 60 cookies total. I have to add in two more bags. I know two 6’s is 12, so there would be 60 and 12 which is 72.”

B.  In order to solve this problem, Abigail separated the problem into two separate new problems. What two problems did she end up solving?

C.  Use a strategy similar to Abigail’s to solve the problem if there were 14 bags with 4 cookies in each bag.

3.  Both Sara’s and Abigail’s strategies are similar in that they both rely on changing the problem into two sub-problems. Characterize the differences in how they did this.

4.  Come up with a strategy (or strategies, if you think of more than one) to solve the following problems. You may try to adapt Sara’s or Abigail’s strategies, or devise something you think is quite different. Do not use the method that is typically taught in school that you are most used to.

A.  29 x 4

B.  29 x 12

C.  36 x 17