PROBLEM:  
             1         1     
            ---   -   ---  =
             5         6

  STEP ONE: Find LCD.

            The LCD of 5 and 6 is 30.

  STEP TWO: Convert fractions

            1 x 6       1 x 5             
           -------  -  -------  =          
            5 x 6       6 x 5

   Think: 

         1     ?         1      ?
        --- = ----      --- =  ----
         5     30        6      30

   To change 1/5 to an equivalent fraction with a denominator of 30, you
   must multiply the numerator and denominator by 6. 

   To change 1/6 to an equivalent fraction with a denominator of 30, you
   must multiply the numerator and denominator by 5.

  STEP THREE: Add numerators and leave the denominator alone.

             6           5         1
            ----   -    ----  =  ----
             30          30       30

  STEP FOUR: Reduce if necessary.

             Not necessary in this example.