Ask students to get out their homework, the Favorite Toppings activity sheet. In this assignment, students surveyed members of their community to determine people's favorite pizza toppings.
Students should locate the topping that was most popular (or if there was a tie, then the two toppings) among the people they surveyed (by looking at the first choice column on the activity sheet). On the chalkboard, record each of the types of toppings and a tally mark for each student’s response.
For example, in the picture above, sausage is the most favorite topping of the group surveyed.
Each student will then create a double-bar graph of their data. Students should use a spreadsheet or graphing program to enter the data. Before starting, have students identify what is being compared for each double-bar (answer: each topping is listed, and then the number of people who chose it as a first choice is shown as a bar next to the number of people who chose it as a second choice.)
Students should have three columns in their spreadsheet file, similar to the three columns on the activity sheet. Then, they can type in the data they collected and use the Chart Wizzard (in Microsoft Excel) to create the double-bar graph.
In their double-bar graphs, students may use two different shadings or colors, one to represent choice 1, and one to represent choice 2. Students should make sure their graphs have a title and that the axes are appropriately labeled.
Once the students have completed their graphs, they can print them out to share with a classmate. In pairs, students can discuss the following questions:
- How does my graph compare to my own preferences?
- Are there any similarities between my graph and my partner’s? What are they?
- What differences exist between our graphs?
- Could I have set up my graph differently yet still displayed the data clearly and accurately?
Once students have had sufficient time to discuss their responses with their partners, return to a whole-class discussion. Have students share some of their findings and observations with the rest of the class.
If time permits, pose the following question to the class for them to think about for tomorrow’s lesson:
If a person is allowed to choose any two toppings (not including "none" or "other", how many different combinations of two-topping pizza are possible?
Students will be exploring this question tomorrow. While not required, students may wish to record this question in a math journal and respond to it.
