Saturday 26 January 2013

Subtracting Fractions

Subtracting Fractions
 "Proper fractions with like Denominators
 7/10 - 6/10 = ?
Since the denominator are alike you don't have to change it. It remains the same.
1. Subtract the numerators together and place the difference over the like denominator
                        7 - 6 = 1 
                                         7/10 - 6/10 = 1/10
"Proper fractions with unlike Denominators" 
1. If it's not like denominators, you have to find the L.C.D. (Lowest Common Denominator) by doing the times tables of both denominators. 
2.When you find the L.C.D. convert the denominator and do the same to the numerator.
4/5 - 1/3 = ?
                                4 x 3 = 12    = numerator                                     1 x 5 = 5     = numerator
                                5 x 3 = 15    = denominator                                3 x 5 = 15   = denominator   
After you converted the fractions you then subtract  the numerators to get the difference.      
                                12 - 5   = 7       
                                15   15 = 15
4/5 - 1/3 = 7/15 
"Mixed fractions with like Denominators"
2 7/8 - 1 4/8 = ?
Since the denominators are alike you don't have to change it. It remains the same.
1. Subtract the numerator's first then the whole numbers.
                                7 - 4 = 3
                                8   8 = 8
2. Subtract the whole numbers.
                                2 - 1 = 1
3. Add the remaining fraction and the remaining whole number.
                                1 + 3/8 = 1 3/8                                                      2 7/8 - 1 4/8 = 3/8
"Mixed fractions with unlike Denominators"
1.If it's not like denominators, you have to find the L.C.D. by doing the times tables of both denominators. 
2.When you find the L.C.D. convert the denominator and do the same to the numerator.               
             2 2/3 - 2 1/2 =?
                               2 x 2 = 4   = numerator                                           1 x 3 = 3  = numerator
                               3 x 2 = 6   = denominator                                      2 x 3 = 6  = denominator
3. After you converted you then subtract the numerators to get the difference.
                               4 - 3 = 1
                               6   6 = 6 
4. Subtract the whole numbers 
                              2 -2 = 0 
5. Add the remaining fraction and the remaining whole number
                             0 + 1/6 = 1/6 
                                                                                      2 2/3 - 1/2 = 1/6 

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