Proportions Lesson 2 Episode 3 (Teachers)

Repeating Your Reasoning

Download Math TaskLink to Geogebra applet

The students continue their work from Episode 2 by looking for more distance and time values that will make the red car go the same speed as the blue car.

Episode Supports

Focus Questions

For use in a classroom, pause the video and ask these questions:

1. [Pause video at 0:39] What are you going to do? How will you know that the combinations of distance and time amounts that you chose work or do not work?

2. [Pause video at 2:29] Compare your table entries with Kate and Christopher’s. What is similar? What is different?

Supporting Dialogue

Support students’ ability to attend to the mathematical claims of others by asking them to:

1. Share their responses to Focus Question #2 by contributing both combinations of values for distance and time that worked and those that did not work, so the class can begin to construct a shared table.

2. Contribute one claim at a time to the class table. Then ask the class who else had the same claim. Then ask the students to share another new claim with the class.