Inquiry Lab II

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SWBAT use bar diagrams to investigate the change in percents.

Big Idea

Will a concrete model help students understand THE CHANGE?


5 minutes
  • POD

As students enter the room, they will have a seat, take out their Problem of the Day (POD) sheet and begin to work on the question on the SMARTboard. The POD allows students to use MP 3 continually based on the discussions we have about the problem each day.

The POD today introduces the concept of finding the percent of discount using bar diagrams. The question breaks the process down into three parts to guide their thinking toward what is necessary to solve the problem. By asking the percent of the discount, the amount of the discount, and the final sale price, I want students to see what the components of the problem are so they become familiar with the process as we explore other problems. I also want them to be familiar with the language of percents. The percent of the discount is not the same as the amount of the discount. Students used these terms interchangeably and they do not mean the same thing. Using the terms interchangeably leads to mistakes when answering questions because they are not properly applying the terms.

The Ink Cartridge Discount Store is having a 25% off sale and the regular price of a cartridge is $20.

What is the percent of the discount?

What is the amount of discount?

What is the sale price?


30 minutes

Students will complete an inquiry lab similar to the lab we completed earlier in the unit. They will use bar diagrams as a concrete model to determine the percent of change in several problems. As they are using the concrete model to  determine the change, we will transition into using possible algorithms to solve problems. Students should be able to see the relationship between an increase and a decrease and develop a problem solving process for finding the amount of increase or decrease without the model. It may be beneficial for students to work with a partner to help with understanding. If they need to work alone to make sure they understand, I will be walking around to ask and answer questions for support.


5 minutes

The exit ticket today will ask students to describe the process we developed for finding the percent of change. I want to know what steps students take to find the percent of change as they define them. This will give me an idea of their thinking and what the process looks like to them. If I am unclear, I can talk to them to clear up my confusion. Sometimes when their thinking is unclear to me, students are able to explain it to me and make their reasoning more clear for themselves as well.


How can you use a bar diagram to show a percent of change?