### Rinorm Austin's Fraction Post

Tuesday, May 12, 2009

When you add fractions you need to find the lowest common denominator. The easiest way to do that is to multiply the two denominators.

2/3 + 1/8= 16/24 + 3/24= 19/24

1/4 + 3/5= 5/20 + 12/20= 17/24

1 3/4 + 2 1/5= 3

You add the 2 whole numbers first.

3/4 + 1/5= 15/20 + 4/20= 19/20

3 9/20

Subtracting Fractions

When you subtract fractions you need to find the lowest common denominator. The easiest way to do that is to multiply the two denominators.

13/15 - 4/5= 13/15 - 12/15= 1/15

4/5 - 1/2= 8/10 - 5/10= 3/10

2 2/3 - 1 1/3=1

You subtract the 2 whole numbers first.

2/3 - 1/3= 1/3

After you subtract the two fractions you get the answer.

Multiplying Fractions

When you multiply fractions, you multiply both the denominators and numerators. If theres a mixed fraction, you turn it into a improper fraction and work from there.

3/4 x 1/2 x 6/7= 18/56= 9/28

As you can see I have simplified the answer to the lowest terms possible.

6/7 x 2/3= 12/21= 4/7

4 1/2 x 1/3= 9/2 x 1/3= 9/6= 1 3/6= 1 1/2

Dividing Fractions

When you divide fractions you use a recipical.
I dont know how to do it on this mac because i dont have paint so look at the other students work :)