Logarithms Lesson 2 Episode 5 (Teachers)

[Pause the video at 0:26] As in the previous lesson, this episode uses a prompt from a fictional student to highlight a common challenge students face when learning (or recalling) rules for exponents. As before, Arobindo and Josh are not persuaded by the faulty claim, and dismiss it quickly. Some students might need more time to reason about the claim, so you may want to give your students some time to think about the fictional student’s claim before watching the video.

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

[Pause the video at 0:51] How can you use the expression Arobindo wrote, 3^0.5 ×3^0.5 ×3^0.5 ×3^0.5, to refute the student’s claim? What should (3^0.5)⁴ equal as an exponential expression with a single exponent?

Ask your students to summarize Josh and Arobindo discussion about (3^a)^b. How did the pair use the beanstalk context to determine and justify that (3^a)^b = 3^ab?