Ultraglide
Advanced Member
Canada
299 Posts 
Posted  09/23/2013 : 11:36:31

You forgot that ALL of 59 5/8 is negative. Certainly 6359 = 4, but 1/8  5/8 = 4/8 or  1/2. This gives 4 + (1/2) or 3 1/2.
The usual method when subtracting a larger fraction from a smaller fraction, is to borrow from the whole number of the first fraction, similarly to what is done when doing subtraction of integers. Here's one way to do it, remembering that you are subtracting (or adding a negative 59 AND 5/8): 63 1/8  59 5/8 = 62 9/8  59 5/8 = 3 4/8 = 3 1/2 Note that the 1 you borrowed is equivalent to 8/8 which is chosen because the denominator is 8. A further note, if the second fraction is still bigger than the first, just keep borrowing until it becomes smaller. 

