12.03.2012 module 1
TRANSCRIPT
5. Representing Areas of Rectangles.notebook
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December 03, 2012
Representing Areas of Rectangles
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Happy Monday!
Please do as much as you can of the first page of the warmup.
If you finish early, please take out Challenges 14 and be ready to start today's lesson.
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Last week, we talked about expressions. What did we say it means to "express" something in Algebra?
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On Friday, we expressed the number of girls in the room as boys minus 2. What is the expression of the number of girls in the room today, in terms of the number of boys?
What is the expression of the number of boys in the room today, in terms of the number of girls?
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On Friday, we also expressed some of the eighth graders in terms of how they like to express themselves. Who was ...
... the girl with the glittery uggs?
... the girl with the Spongebob lunch box?
... the boy with the furry winter hat that gets passed around to everyone else?
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What is another way to express two $1 bills?
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We need someone to read Page 19, loudly and clearly.
Does this trade seem fair? Why or why not?
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How can you find the area of these two plots of land to see which one has more space?
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In this problem you will test several cases and record your data in a table. Your table will help you to see patterns that will tell you more about situations like these.
If the side length of the square is n, and we add 2 to the length, how can we express the new length?
If the side width of the square is n, and we subtract 2 from the width, how can we express the new width?
If the original area could be expressed as length x width, how can we express the new area?
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What patterns do you see in the table?
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What would be the length and width of a new rectangle if the original square had sides of 100 feet?
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What is the equation for the area of the orginal square? (#3)
What do you notice about the area of the new rectangles compared to the original square? (#2)
How can we write the equation of the area of the new rectangle? (#4)
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Original Square Lot vs. New Rectangular Lot
Length Area Length Area
10 109 98 8
a = n2 a = n2 4
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Modeling Polynomials with Algebra Tiles
x2
x1
x2
x1
(2x2 + 3x + 1) + (x2 + 2x 2)
x
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Modeling Polynomials with Algebra Tiles
x2
x1
x2
x1
(2x2 3x + 1) (3x2 + 2x 2)
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What is the equation for the area of the orginal square? (#3)
What do you notice about the area of the new rectangles compared to the original square? (#2)
How can we write the equation of the area of the new rectangle? (#4)