Grades 9-12

# Where Does the Price of Pizza Come From?

### Objective

Students will be able to:

- Construct a graph using tabular data for buyers/sellers.
- Compare and contrast two specific linear functions
- Explain how prices are determined in a market.

### Standards

### Concepts

In this economics lesson, students will examine data for buyers and sellers to learn how prices emerge in a market.

### Resources

### Procedure

Warm-up

Use the PowerPoint Slides to guide your students through the lesson. Open the slide deck and use slides 3-8 to review both warm-up activities. Students will work through two warm up problems: one on pizza delivery fares and the other on sales of pizza slices at a baseball game. In each problem, students are challenged to create tables, plot points on a graph, and determine the equations and slope of the lines. At a baseball stadium, the vendors start out with 24,000 slices of pizza. They know they will sell about 4,000 during each 30-minute segment of the game.

Modeling

Display the slide titled “Where Does the Price of Pizza Come From?” Discuss the following:

Raise your hand if you have eaten pizza in the last week. Wow! Many of you have been eating pizza. What price did you pay? (Record prices on the board.) Where do you suppose the price for the pizza came from? (Record some student responses on the board.) We will begin our investigation into where and how prices emerge. Today, you will begin the investigation by looking at some data related to pizza prices. You will graph two sets of data and write the equations for these two data sets. You will also learn some new vocabulary terms to describe the data you are investigating.

Group Activity

Divide students into small groups of 2-3. Distribute Where Does the Price of Pizza Come From? worksheet. Review instructions for the activity and provide students with approximately 20 minutes to complete Parts I and II of the activity in their groups. Circulate the room to provide assistance to groups when needed. Debrief the activity by looking at the results of the graphing. Call on two groups, one to graph Part A on one side of the board and the other to graph Part B on the other half of the board. Check the graphs for accuracy. The graphs are also reproduced on slides 10 and 11.

Call on two different groups to come to the board to write the equations for Graph A [y = (1/250)(x)} and Graph B [y = 20 – (1/250)(x)]

Students will participate in a Kahoot! game that can be played individually or as a team using any computing device or a cell phone. Compare and Contrast using the Kahoot! game. Answers to this part of the activity are also reproduced on slide 12 of the PowerPoint.

Individual Activity

Remind students that we are still trying to find the answer to today’s question, Where does the price of pizza come from? Inform students that Part III of Where Does the Pizza Come From? worksheet will provide some much needed insight. Review instructions for Where Does the Pizza Come From? worksheet, Part III. Provide approximately 10 minutes for students to complete the activity.

### Assessment

Call the group back together and discuss the results. Ask for two students to each graph the buyer’s and seller’s line and determine the intersection. Ask another student to label the three vocabulary words on the graph. Display slide 13 from the PowerPoint and highlight the key vocabulary terms: demand, supply, price, equilibrium.

Use slide 14 to wrap-up the lesson. Have students fill in the blanks for the following statements and submit their answers before the end of class. Review the answers the next day in class. The answers are on slide 15 of the PowerPoint.

### Extension

Activity 1

Use the Internet to find the price of large, two-topping pizzas in your area. Discuss why prices may vary between businesses.

Activity 2

Invite students to create and administer a survey for their class or school to determine the demand for large, two-topping pizzas.

## Related Resources

Marginal Revolution University

Grades 9-12

### Valentine's Day Demand Interactive

Grades 9-12

### What Can We Do About Pollution?

Grades 9-12