WEBVTT

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Let's see if we can
write 0.15 as a fraction.

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So the important
thing here is to look

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at what place these
digits are in.

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So this 1 right over here,
this is in the tenths place,

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so you could view
that as 1 times 1/10.

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This 5 right over here is
in the hundredths place,

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so you could view
that as 5 times 1/100.

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So if I were to rewrite
this, I can rewrite this

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as the sum of-- this 1
represents 1 times 1/10,

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so that would literally
be 1/10 plus--

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and this 5 represents
5 times 1/100,

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so it would be plus 5/100.

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And if we want to
add them up, we

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want to find a
common denominator.

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The common denominator is 100.

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Both 10 and-- the
least common multiple.

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100 is a multiple
of both 10 and 100.

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So we can rewrite this
as something over 100

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plus something over 100.

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This isn't going to change.

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This was already 5/100.

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If we multiply the
denominator here

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by 10-- that's what we did;
we multiplied it by 10--

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then we're going to have to
multiply this numerator by 10.

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And so this is the
same thing as 10/100.

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And now we're ready to add.

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This is the same thing
as-- 10 plus 5 is 15/100.

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And you could have done that
a little bit quicker just

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by inspecting this.

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You would say, look, my
smallest place right over here

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is in the hundredths place.

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Instead of calling this
1/10, I could call this

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literally 10/100.

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Or I could say this
whole thing is 15/100.

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And now if I want to reduce
this to lowest terms,

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we can-- let's see, both the
numerator and the denominator

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are divisible by 5.

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So let's divide them both by 5.

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And so the numerator,
15 divided by 5, is 3.

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The denominator, 100
divided by 5, is 20.

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And that's about as
simplified as we can get.