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## Topic G: Division of fractions and decimal fractions

Current time:0:00Total duration:2:32

## Video transcript

Tracy is putting out
decorative bowls of potpourri in each room of the
hotel where she works. She wants to fill each bowl
with 1/5 of a can of potpourri. If Tracy has 4 cans of
potpourri, in how many rooms can she place a
bowl of potpourri? So she has 4 cans, and
she wants to divide this 4 cans into groups
of 1/5 of a can. So if you have 4 of
something and you're trying to divide it into
groups of a certain amount, you would divide by
that amount per group. So you want to divide 4 by 1/5. You want to divide 4 cans of
potpourri into groups of 1/5. So let's visualize this. Let me draw one can of
potpourri right over here. So one can of potpourri can
clearly be cut up into 5/5. We have it right over here. 1, 2, 3, 4, 5. So 1 can of potpourri
can fill 5 bowls if you put 1/5 in each bowl. Now, we have 4 cans. So let me paste these. So 2, 3, and 4. So how many total bowls of
potpourri can Tracy fill? Well, she's got 4 cans. So this is going to
be equal to-- let me do this is the right
color-- this is going to be equal to, once
again, she has 4 cans. And then for each
of those cans, she can fill 5 bowls of potpourri
because each bowl only requires a 1/5 of those cans. So this is going to be the
same thing as 4 times 5. Or we can even write
this as 4 times 5 over 1. 5 is the same
thing as 5/1, which is the same thing
as 4 times 5, which, of course, is equal to 20. She can fill 20 cans-- or I
should say, with her 4 cans, she can fill 20
bowls of potpourri. Now, just as a
review here, we've already seen that
dividing by a number is equal to multiplying
by its reciprocal. And we see that right over here. Dividing by 1/5
is the same thing as multiplying by the
reciprocal of 1/5, which is 5/1. So she could fill up
20 bowls of potpourri.