Question 603764
I was wondering how you would work out {{{1/3}}} - {{{2/11}}} because 3 doesn't go into 11. I am very confused. Thank-you
<pre>
Since 3 doesn't go into 11, you have to think of a number that BOTH
3 and 11 WILL go into.

Here's what you do:

1.  Think of a number which 3 and 11 will BOTH go into.  If you can't
    think of anything smaller, then multiply them together, and both
    3 and 11 will go into it. 

    3 times 11 = 33

2.  Now 3 goes into 33 11 times, and 11 goes into 33 3 times.

3.  Multiply the {{{1/3}}} by the fraction {{{11/11}}} and multiply
    the fraction {{{2/11}}} by the fraction {{{3/3}}}.  [It's OK to
    do that because those are just 1 and you can multiply anything
    by 1 and it won't change:

    {{{1/3}}}×{{{11/11}}} - {{{2/11}}}×{{{3/3}}}

4.  Multiply numerators and denominators:

    {{{11/33}}} - {{{6/33}}}

5.  Now they both have the same denominator so all you have to do is
    subtract their numerators 11 - 6 and get 5, and then put that 5 
    over that common denominator 33 and you have

    {{{5/33}}}

    That's the answer.

    Here is the way you write it on your paper:

    {{{1/3}}} - {{{2/11}}},  11×3 = 33 <-- that's called the LCD
    {{{1/3}}}×{{{11/11}}} - {{{2/11}}}×{{{3/3}}} 
    {{{11/33}}} - {{{6/33}}} 
    {{{5/33}}} 
   
Edwin</pre>