Showing Revision 3 created 05/25/2016 by Udacity Robot.

1. Title:
   Percents - Visualizing Algebra
2. Description:

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   We're done working with exponents for now, but we'll come back to them later.
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   Let's look at some other ways that we can use decimals. We're going to look at
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   decimals and percents. Decimals and percents are often used in currency and in
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   commercial business. We can buy shoes, sweaters, or electronics on sale. And we
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   often want to know how much does something actually cost. By the end of this
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   segment, you'll be able to find out how much an item cost, like a new pair of
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   shoes. So, here's the problem that we're going to have you answer and come back
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    to later. A pair of shoes costs $80 and is on sale for 44% off, what will you
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    pay for the shoes? The first thing we need to recognize is this problem has a
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    percent in it. Percent literally means per 100 or out of a 100. I can write
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    44 percent another way.
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    I know it's 44 out of 100 or 44 divided by 100. 44 divided by 100 is the same
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    thing as 0.44. Here's a grid of a 100 squares, or I have 1 block. Of these 100
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    pieces, I'm going to have 44 of them. So, I'd have 10, 20, 30, 40, 44 blocks out
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    of a 100 or 0.44 and that's this written as a decimal, 0.44. Okay, here are some
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    other percents. I can have 23%, 6%, or 200%.
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    I'm going to convert these percents to decimals. Sometimes, we need to convert
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    percents to decimals in order to use them in problems or to multiply. Okay, so
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    let's use these 100 blocks to help us out. Here, I have 23 squares shaded out of
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    100. So, 23 divided by 100. As a decimal, that's 0.23. For 6%, I'm going to have
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    6 blocks out of a 100. So, I have 6 blocks out of a 100 or 6 hundredths, 0.06
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    Notice that 6 has to be in the hundredths spot. For 200%, I know that I have to
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    do something different. I can color in 100 of the squares in this 1 block. So, I
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    have a 100 blocks shaded, but I need 200%. This is only a hundred out of a
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    hundred, that's a 100%. 200 percent means 200 out of 100. I know one of these
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    squares represents a hundredth, so I have 200 hundred hundredths, or I just have
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    2 or 2 blocks. Okay. There's actually a pattern here that we want to notice.
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    Let's look closely at the decimal places. Here in 23%, the decimal is here and
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    then it ended up here. For 6%, the decimal started here and ended up here. For
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    200%, the decimal started here and ended up there.
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    Let's have a quiz behind what's going on with this pattern. What do you notice?