SWBAT explain the use of repeated addition and multiplication to solve a word problem

This multi-step word problem requires students to use repeated addition or multiplication to solve a word problem.

5 minutes

This lesson begins with reviewing the steps for solving word problems established in a previous lesson. It is important for my students to have a sequence and specific steps to follow to solve word problems. This allows for the students to look at the process rather than just jumping to an immediate answer, and possibly missing key information and steps.

Creating a plan for word problems includes:

- Rewrite the question from what is being asked in the word problem.
- Identify the key information.
- Draw a model.
- Write the number sentence.
- Answer the question from step 1.
- Explain your solution.

The last step is critical for the Common Core Standards, and one that we need as teachers so that we can correctly assess student work. The Introduction to the CC Math Standards states:

These standards define what students should understand and be able to do in their study of mathematics. But asking a student to understand something also means asking a teacher to assess whether the student has understood it. But what does mathematical understanding look like? One way for teachers to do that is to ask the student to justify, in a way that is appropriate to the student’s mathematical maturity, why a particular mathematical statement is true or where a mathematical rule comes from.

10 minutes

For this lesson, the students use a word problem from the Exemplars website, which provides this math task, 3 Fish Limit, for free.

The students work in partners using the six steps addressed in a similar lesson, Fun Park Rides. Creating their plan is the focus as students work together with limited supports and interventions from me. I want the students to create their own plans, identify the key information, and craft an explanation to present to other students at the end of this lesson.

15 minutes

Although the students are working together as partners, each student is responsible for creating a plan and poster to present their solutions. I want each student to take ownership of the work they have accomplished, and to also be able to explain how the arrived at their solution. This is important because in some partnerships, one student will take over and complete all the work leaving one student without the opportunity to develop their own understanding.

10 minutes

To end the lesson I have the students share their thinking with another group of students to compare their strategies. I have them focus on the explanation so that the students can critique the work of others and implement the Common Core Math Practice of constructing an argument and critique the reasoning of others. I create the groups with the intent of changing the working dynamic, placing students with those they don't normally work with. These presentations are very informal, and if I find that students needs more assistance or direction, I change the structure to a whole group.