standard_description: Derive the formula for the sum of a finite geometric series (when the common ratio is not 1), and use the formula to solve problems. For example, calculate mortgage payments.
problem_activity: Narrative
The purpose of this activity is for students to analyze what they have learned from the data and representations in the previous activities and to share their findings. In this activity, students select two things they learned and illustrate them using a tape diagram.
Monitor for tape diagrams that can be displayed during the lesson synthesis and compared to the bar graph selected in a previous activity. While the graph and diagram do not have to be from the same pair, it would be helpful for students to see data from the same survey displayed with different representations.
To add movement to this activity, consider a gallery walk. Students can make their diagrams on poster paper. As students walk around the room, they select a few diagrams and determine what information they learn about their class based on the diagram and equation.
Launch
Groups of 2
“You and your partner are going to draw a diagram. Your diagram should compare two facts you learned from your survey.”
“Decide with your partner which 2 facts you want to share with the class and how you will compare the two facts.”
1 minute: partner discussion.
Activity
5 minutes: independent work time
Students check in with their partners to be sure their representations make sense and are accurate.
3 minutes: partner discussion
Monitor for a few examples of accurate tape diagrams and equations.
Student Facing
Draw a diagram. Your diagram should compare two facts you learned from your survey.
Write an equation that represents the comparison.
Student Response
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Activity Synthesis
Display selected student work.
“What information does this diagram or equation tell us about our classmates?”
“Where do you see this equation in the diagram?”


aligns: no