Word problems are typically not students’ or teachers’ favorite part of the math lesson. When I talk with teachers, they are frustrated with teaching multiplication word problems.
I think one of the things we have been missing is teaching students the structure of what is involved in any multiplication word problem. “Look for and make use of structure” is the Common Core Mathematical Practice Standard 7. I have seen time and time again this practice playing a significant role in how a student is able to understand the content being taught. With a good understanding of the structure of multiplication in the context of a story, word problems can be created and understood.
I went into a fourth grade class and tested this idea out. We began the lesson brainstorming different scenes that would be engaging for the students. I gave the students cards that were labeled: group, in each group, and total. I explained that in every multiplication problem there are three numbers involved: what is in each group, how many groups, and what is in the total. Then we walked through as a class one of the scenes.
I modeled writing a word problem using students on a bus. At the end of the lesson, the students got into groups and wrote one or two problems themselves. Here are a few examples of what they wrote.
- There were 2 malls. They each had 10 stores. How many stores were there altogether?
- There were 4 trailers. Each trailer holds 14 cows. How many cows were there?
- There were 8 kids in the candy store. They each ate 32 pieces of candy. How many pieces of candy were eaten?
- There were 5 stores. Each shopper bought 500 shirts in each store. How many shirts did they buy in all?
And so teaching multiplication word problems becomes easier. Once students understand how to brainstorm their own groups and what is in each group, they will write endless word problems–all about things they are interested in. Students will become engaged and build word problems through the lens of the structure of multiplication.