The students apply what they learned in the previous episodes to explore a new situation in which the length of a media room is increased by 3 meters and the width is increased by 2 meters. They make a drawing and write equations to find the area of the new media room in different ways.
Episode Supports
Students’ Conceptual Challenges
As before, in Episode 3 of this lesson, the students are asked to identify groups of certain units within their drawing, this time two groups of eight. Once again, instead of drawing groups that align with the dimensions of the grid (e.g., two rectangles, each of which have dimensions 1 unit by 8 units), the students draw other groupings (e.g., two rectangles, each of which have dimensions 2 units by 4 units, [11:15]). While this way of seeing the groups is not wrong, it is helpful to be able to see the groups aligning with the dimensions of the rectangle, as Emily eventually does.
Focus Questions
For use in a classroom, pause the video and ask these questions:
[Pause the video at 3:14] If Antonio’s media room is 8 m long and 5 m wide, and Miguel’s media room is 3 m longer and 2 m wider than Antonio’s media room, what is the area of Miguel’s media room? Use a drawing to help you find the area.
[Pause the video at 8:00] Mauricio and Emily used the equation 11 × 7 = 77 m2 to find the area of Miguel’s media room. Use the drawing they produced (or your own) to write additional equations that also express the area of Miguel’s media room.
Supporting Dialogue
[Pause the video at 5:18] What parts of the diagram should Emily and Mauricio label? What is the area of each of those parts?
[Pause the video at 9:23] Take turns with a partner to explain where in the drawing you see each number in the new equation that Mauricio just wrote: 8 × 5 + 8 × 2 + 3 × 2 + 3 × 3 = 77.
