Logarithms Lesson 1 Episode 5 (Teachers)

The prompt at 0:25 highlights a common challenge that students face when learning (or recalling) rules for exponents. Josh and Arobindo eagerly dispel this incorrect rule by leveraging the beanstalk context and the work they’ve done in prior episodes. You may want to solicit ideas from your students before watching this episode. If students think the friend is correct, you may consider having a class debate before letting Arobindo and Josh weigh in.

For use in a classroom, pause the video and ask this question:

[Pause the video at 0:53] Can you rephrase Josh’s argument for why 3² ×3⁶ is 3⁸? Do you agree or disagree with Josh?

After watching the video, ask students to summarize Josh and Arobindo arguments for why they disagree with the friend. After some discussion, you can point out that Josh’s argument seems to utilize ideas about exponents in general while Arobindo’s argument relies on the context of the beanstalk and the number line. Ask your students to discuss how these two representations (the symbolic representation that Josh used and the visual/contextual representation that Arobindo used) are connected.