## Monday, March 12, 2007

### SUBTRACTING FRACTIONS .

When you want to subtract fractions that are a mixed number you should convert the mixed number into an improper fraction, then subtract them as fractions.Heres an example 5 1/8 - 2/3 = ? .. convert the mixed number into an improper fraction. which is 41/8 find the most common denominator and that is 24. your fraction now is 123/24. SINCE 8 x 3 = 24 and 41 x 3 = 123. The other fraction is 16/24 because 8 x 2 = 16 and 8 x 3 = 24. Then subtract 123 from 16 and that equals 107/24.. if you want to convert it back to a mixed number you have to see how much 24 goes into 107 . which is 4 times, then how much remains and that would be 11. mixed fraction is 4 11/24...
If the fractions aren't in a mixed number.. heres the way to do it.
2/3 - 3/5 = 10/15 = 9/15 = 1/15 .. multiply the denominators by each other ( 5 x 3 =15) .. then cross multiply 2 x 5 = 10 and 3 x 3 = 9 .. fraction is now 10/15 and 9/15 then subtract 10 from 9 and that gives you 1/15 ..
If the fractions have different denominators
1) Find the least common denominator.
2) Find the equivalent fraction using this denominator.
3) Subtract the fractions, if you could reduce then you should.