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- [Instructor] I'm here at the Khan Academy exercise
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called Find One on the Number Line
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and they're asking us to do exactly that.
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It says, "Move the dot to one on the number line,"
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and it's a little interactive dot
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that I can move around.
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And so, let's think about how I would do it
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and I always encourage you,
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pause this video and see at least how
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you would think about doing it
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or put your finger on the screen where you think one is
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and then we'll work through it together.
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All right.
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So they've told us where zero is
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and they've told us where seven fourths is.
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So one thing I could do is
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I could say well how many of these equal spaces
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does it take me to get from zero to seven fourths.
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So let's see it's one, two, three, four, five, six, seven.
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So if it takes seven equal spaces to get to seven fourths,
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that means that each of these spaces is one fourth
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because then it would be one fourth, two fourths,
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three fourths, four fourths, five fourths, six fourths,
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and seven fourths.
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All right, we're making some good progress.
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So where would one be?
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Well, one would be four fourths.
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So we would go one fourth, two fourths, three fourths,
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and then four fourths.
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So that's where one is.
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So the important thing to realize is the only way
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we knew that each of these, each of these gaps,
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or each of these spaces from one hash to the next,
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the way that we knew that each of those is a fourth
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is by saying hey look, seven of those equal spaces
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get us to seven fourths,
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so each of these must be a fourth.
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So four of those, four fourths, would be equal to one.
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Let's do another example.
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So here, we're said, we're told to move the dot
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to one on the number line.
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So put your finger on where that would be on the screen.
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Pause the video and do that.
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All right.
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In some ways this is a little bit easier
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because they told us that going from zero
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to the next little cross or hash, I guess you could say,
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whatever you want to call these things, is one sixth.
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So what is one?
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Well, one or one whole is six sixths.
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So this is one sixth, two sixths, three sixths,
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four sixths, five sixths, and then six sixths.
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So there we go.
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That is where is one is on this number line.