Exponentials Lesson 4 Episode 3 (Teachers)

Repeating Your Reasoning

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Josh and Arobindo use their new timeline to create an expression that represents the height of the new beanstalk on Day 100.

Episode Supports

Focus Questions

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

[Pause the video at 0:30] Make a prediction about the height of the beanstalk after 100 days. Write your prediction as an expression using the quantities given in the video: a starting height of 2 cm, a beanstalk that triples its height every day, and a length of time of 100 days.

Supporting Dialogue

After watching the video, ask students to make sense of the expression 3100. Listen for, and highlight, discussions that focus on the expression as the number of times taller the beanstalk is on Day 100 compared to Day 0 and also as a growth rate for any 100-day period of time. For example, 3100 could also represent how many times taller the beanstalk is on Day 231 compared to Day 131.