Exponentials Lesson 7 Episode 2 (Teachers)


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The students create several different expressions for the height of the beanstalk at Day 2.5 and justify them using the timeline.

Episode Supports

Focus Questions

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

  1. Pause the video at 1:05] Examine the timeline from the video and write several different expressions for the height of the beanstalk on Day 2.5. Compare your expressions to those that Josh and Arobindo come up with in the video.
  2. [Pause the video at 4:59] Can you explain to a partner why Arobindo and Josh are able to write the height of the beanstalk on Day 2.5 as ?
  3. [Pause the video at 6:20] Look at the work that Josh and Arobindo have done. Connect the relationships shown on the timeline to the expression 31 x 31 x 30.5. Can you connect those relationships to the expression from earlier in the video?

Supporting Dialogue

After watching the video, display the following expressions: 

  • 15.888
  • 9 • 3½
  • 32.5
  • 32 • 30.5

Ask students to talk with a partner to make sense of each expression using both the timeline representation and the context of the growing beanstalk. After some time, open up the discussion to the entire class so that students can hear multiple different ways of thinking about the meaning of each expression and how to link it to the context and the timeline.