Kate and Christopher make sense of what going the same speed looks like in the Races applet.
For use in the classroom, pause the video and ask these questions:
1. [Pause video at 1:02] Are they done? What does it mean to choose the number of miles and the number of minutes for each car so that the two cars go the same speed?
2. [Pause video at 2:31] Christopher said that he thought the two cars would hit their destinations at the same time. Would that mean that the two cars would be traveling at the same speed? How do you know?
Support the students’ ability to encourage and attend to the claims of other students by asking them to work with a neighbor:
1. Identify the two mathematical claims that Kate and Christopher made in this episode.
2. Identify some ideas about how to encourage students to share their mathematical claims. What encourages you to share your mathematical claims? What makes it hard to share?