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Dividing Fractions - Is there another way?

There are some division problems involving fractions that are pretty easy to do. For instance:

   6/8
  _____ 
 
   3/8
 

How many 3/8 are there in 6/8? If we ask it this way, we can do this in our heads.

   6/8
  _____ = 2
 
   3/8

But what about something like

   7/8
  _____ = ?
 
   3/5

How many 3/5 are there in 7/8? Can you calculate that in your head? Some people would change the fractions to decimals and use a calculator (.825 divided by .6). Others would rewrite the fractions using common denominators.

   (7/8) * (5/5)     35/40     35/40     40     35
  _______________ = _______ = _______ * ____ = ____

   (3/5) * (8/8)     24/40     24/40     40     24
   

That's a pretty long process.

Use whatever method works best for you, but for many math students and teachers, "invert and multiply" is the strategy of choice.

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