Parabolas Lesson 2 Episode 5 (Teachers)

Repeating Your Reasoning

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Sasha and Keoni find the x-value of a point on the parabola with a y-value of 10.

Episode Supports

Focus Questions

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

1. [Pause video at 1:06]. Keoni labeled one side of the triangle 9 and another side 11. Where are those values coming from? Does he have to count?

2. [Pause video at 2:56]. Keoni wants to know what 6.322 is. Sasha exclaims, “say it’s 40.” What do you think her reasoning is?

Supporting Dialogue

Invite your students to consider the varied student work in the room:

1. As students work, you can walk around the room to examine the kinds of methods of solving the problem that are being used. When you find two different ways that the students are expressing their work, asks the students if they would be willing to share their work with the class or allow you to share it with the class.

2. As students, or you, share their work, ask a student in the classroom to restate and compare what they heard. For example: “Can someone restate William’s methods?” and “What is different about the methods?”

Math Extensions

1. Find the x-value of a point on the parabola when the y-value is ½.

2. Find the x- value of a point on the parabola when the y-value is √30.