Logarithms Lesson 6 Episode 3 (Teachers)

Repeating Your Reasoning

Download Math Task

Arobindo and Josh fill in the blanks of the equation log3 (___) + log3 (___) = log3 (1,000) to make the equation true. They justify their answer.


Episode Supports

Focus Questions

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

  1. [Pause the video at 0:56] Fill in the blanks to create a true equation: log3(__) + log3(__) = log3(1,000). Use a number line to defend your choices.
  2. [Pause the video at 2:01] Why do you think Arobindo and Josh said that log3100 is between 4 and 5?

Supporting Dialogue

Near the end of the episode [5:15], the instructor asks about the relationship between 2.1, 4.2, and 6.3. Arobindo and Josh say you add them together. Ask your students to elaborate on that claim: Why do we add them together, and how does that relate to the moldy pizza context? Can you see these quantities as elapsed time in the timeline?