Mauricio and Emily rewrite their equation from Episode 1, this time using only two variables. They test their new equation using a length of 4 inches for each side of the square piece of fabric.
Episode Supports
Students’ Conceptual Challenges
In this episode, Mauricio and Emily work to express the area of Zara’s square piece of fabric using only one variable. They know the difference between squares and rectangles, but as seen in the previous episode, they weren’t ready to extend that understanding to more efficiently choose variables for the context. The teacher encourages this connection by explicitly asking the pair to use what they know about squares to write the area using only length or width.
Focus Questions
For use in a classroom, pause the video and ask these questions:
[Pause the video at 2:08] How could you use just the length or just the width of the square to represent its area?
[Pause the video at 3:35] Before watching Emily and Mauricio, how would you draw Zara’s square piece of fabric if the length is 4 in? What would the area of the fabric be?
[Pause the video at 6:07] Can you draw a picture and use it to write an expression for the area of Zara’s fabric when the length is some unknown number?
Supporting Dialogue
[Pause the video at 0:25] Tell a partner what you know about squares. What makes them special? How could you use this to rewrite the area of Zara’s fabric?
