Algebraic Expressions Lesson 5 Episode 6 (Teachers)


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Haleemah and ET explain what each symbol and operation of their general equation means in the cobblestone context. 

Episode Supports

Focus Questions

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

  1. [Pause the video at 1:22] Ask your students to restate ET and Haleemah’s explanation for what each x means, relative to the diagram, in the first expression x • x.
  2. [Pause the video at 2:03] Ask students what they think x • x means in this situation. If they restate the initial description of one x representing the number of stones in a column and the other x representing the number of columns, ask them to think about the result of x • x  and what that means in the cobblestone context.

Supporting Dialogue

At 2:50, ET is asked to explain where in the diagram he sees the “+ x” from his equation. He states that it is from the extra column in the middle section of gray stones. As an example of this, he points out how in the Size 11 figure there are 12 columns, each with 11 stones; so the 12th column would be the “+ x”. Ask your students to discuss ET’s explanation with their partner. After they have a chance to talk, ask them if they see a different expression for the middle section of stones, and if so, to explain how they see it now in relation to the diagram and what ET explained. Students might now see the middle section of stones as being a rectangle with dimensions x and x + 1.