Christopher and Kate figure out how many miles a car should travel in one minute so it goes the same speed as a car traveling 10 miles in 4 minutes. This results in a unit ratio.
For use in a classroom, pause the video and ask these questions:
1. [Pause video at 1:23] Can someone revoice Christopher’s idea?
2. [Pause video at 2:30] Make your own diagram that shows why a car traveling 2.5 miles in 1 minute travels at the same speed as a car traveling 10 miles in 4 minutes.
When engaging in the tasks in class, invite your students to consider the varied student work in the room by considering the student diagrams from Focus Question #2:
1. As students build their own diagrams, find two different ways that the students are expressing their ideas and ask the students if they would be willing to share their work with the class.
2. As students share their work, ask another student in the classroom to compare what they heard. For example: “Can someone say how Diana’s and Alma’s diagrams are different? How are they similar?”