Fractions: What are the rules for adding negative and positive fractions?
Calculate [tex]\frac{1}{125} - \frac{1}{250}[/tex]. This confuses me. Can you help?
Answer (2)
The rule is: Before you can add or subtract fractions, they must have the same denominator.
For this little problem, don't worry about the signs yet. Just make both fractions have the same denominator. I suggest you change the first one to something over 250.
When your fractions have the same denominator, you get the sum or difference like this:
-- The numerator of the answer is the sum or difference of the two numerators.
-- The denominator of the answer is the same as the denominator of the two fractions.
To subtract the fractions 125 1 and 250 1 , convert to a common denominator of 250. This gives you 250 2 − 250 1 = 250 1 . The final answer is 250 1 .
;
