Subtracting fractions
Last updated: 11 Nov 2008
Subtraction is performed in exactly the same way as addition but you subtract the numerators rather than add them.
Simple example
So in the case that the denominators (the lower numbers) are the same, you simply subtract one numerator (the top numbers) from the other.
More complex example
In this example we must find a common denominator before carrying out the subtraction.
The lowest common denominator of 4 and 5 is 20 so the fractions must be converted to 20ths first.
