Multiplying Unlike Fractions

Date: 4/1/96 at 7:14:46
From: Leigh Ausband
Subject: Multiplying unlike fractions

From Mrs. Fields' seventh grade math classes at 
Robert Smalls Middle School, Beaufort, SC.

Dear Dr. Math,

What is the fastest way to multiply unlike fractions? For
example 5/9 * 2/12.

Kevin O'Brien

Date: 4/2/96 at 4:2:32
From: Doctor Jodi
Subject: Re: questions for Dr. Math: Kevin O;Brien

Hi Kevin!

Multiplying unlike fractions isn't any different from multiplying 
fractions with the same denominator, surprisingly enough!

We just multiply the numerators and multiply the denominators.

So

  5     2      10
  -  * --  =  ---
  9    12     108
 
We can then put 10/108 into lowest terms:


 10      5    2      5
 --  =  --  * -  =  --  * 1
108     54    2     54


So 5/9 * 2/12 = 5/54

Ok, so here's a question for you Kevin:

what's 3/8 * 5/6?

-Dr. Jodi
  http://mathforum.org/dr.math/