Adding and subtracting fractions with unlike denominators

eg.

1/4 + 1/6 or 3/5 -1/2

You must find a common denominator to make the bottom number the same.

Common Denominator- a common multiple of the denominators of the set of fractions.

eg.

a common denominator for 1/4 and 1/6 is 12 because a common multiple of 4 and 6 is 12.

Multiple- the product of any given number and natural number like 1,2,3.....

Eg.

some multiples of 3: 3,6,9,12,15,18

You must find the 1st 5 multiples of each number

To make a common denominator you must find L.C.M- lowest common multiple

4 and 6

6- 6,12,18,24,304- 4,8,12,16,20

the L.C.M is 12

Once you find a common denominator, you make an equivalent fraction

eg.

3/12 + 2/12= 5/12