Lesson 7

The purpose of this warm-up is to elicit the idea that bar graphs need a title and a scale in order to be able to communicate information clearly (MP6), which will be useful when students draw a scaled bar graph in a later activity. During the synthesis, focus the discussion on the missing scale.

• Groups of 2
• Display the graph.
• “What do you notice? What do you wonder?”
• 1 minute: quiet think time

• “Discuss your thinking with your partner.”
• 1 minute: partner discussion
• Share and record responses.

• “Could each unit or each space between two lines on the graph represent 1 student? Why or why not?” (No, because that would mean half of a student likes broccoli, cauliflower, and peas.)
• “If each unit on the graph represents 2 students, how many students have broccoli as their favorite vegetable?” (13) “What if it represents 4 students?” (26)
• “How should you decide on a scale for your graph?” (Think about how many people you surveyed and use a scale that will fit them on your graph. Use a scale that will make the bar graph easy to read.)

The purpose of this activity is for students to make a scaled bar graph to represent the data from the survey conducted in the previous lesson (MP2). The synthesis focuses on how students chose the scales for their graphs. Students will use their scaled bar graphs in the next activity.

• Each group of 4 needs the survey data from the previous lesson.

• Groups of 4
• “We are going to represent the survey results from the previous lesson using scaled bar graphs. What are some things you’ll need to consider as you make your graphs?” (The scale I will use so I can fit my graph on the grid provided. I'll have to decide how I will title my graph.)
• 1 minute: small-group discussion
• Share responses.

• “Work with your group to create a scaled bar graph that represents your survey data. As you work together, each member of the group should make their own graph.”
• 10–12 minutes: small-group work time

• “Tell me about how you chose the scale for your graph.”
• “How could you adjust your scale so the graph fits all of the data you collected?”

• Invite 2-3 groups to share their graphs.
• “How did you decide what scale to use for your graphs?” (We made sure that every category would fit on the graph. We thought about making the graph easy to read.)

The purpose of this activity is for students to ask and answer questions using their bar graphs from a previous activity. Students work with the group they collected survey data with to create questions that can be answered with their bar graphs. Then students are paired up with a new partner to use these questions to practice solving one- and two-step “how many more” and “how many fewer” problems using information presented in scaled bar graphs (MP2).

• Each group needs the bar graphs they created in the previous activity.

• Groups of 4
• “Work with your group to complete these sentences to write questions that could be answered with your bar graph.”
• 5–7 minutes: small-group work time
• Have each group share one of their questions and how they came up with the question.

• Groups of 2
• Be sure students have a partner that wasn’t in their group in the previous activity.
• “Use your partner's graph to answer the questions your partner wrote. They’ll answer your questions while you’re answering theirs. Then you’ll spend a few minutes checking each other’s work.”
• 7–10 minutes: partner work time
• Have students switch partners again and repeat as time permits.

• “What was the most interesting question you answered about a scaled graph?”