Alex+and+Kyle+8-17

Lowest common Denominator
It is the smallest common fraction of the Denominator. We use LCD because it makes fraction operations easier.

Numerator/Amount of pieces Denominator/Size of pieces 2/3 = 4/6 + 5/6 9/6 1 3/6 or 1 1/2

Multipling
4 x 1/2 2 4/2 = 2 With fractions any whole # over one still equals the original amount.

3/4 x 1/2 = 3/8 when multiplying fractions you do not need a common denominator.

4 3/5 x 2/6 = 23/5 x 2/6 = 46/301 = 16/30 = 1 8/15

2 1/8 x 3 3/5 = 17/8 x 18/5 300/40 divid by 8 both numerator and denominator.

3/4 x 1/3 = 3/12 1/4

7/8 x 6/21 42/168 21/84 = 1/4

Word Problem A recipe for 4 dozen cookies calls for a 3/4 cup of sugar. How much sugar is needed to make 2 dozen cookies. 3/4 x 1/2 = 3/8

Adding
Find the LCD first, than add the Numerators together and put the answer to the Denominators. Example 2/5 = 4/10 9/10 = 9/10 4/10 + 9/10 = 1 3/10

2/3 x by 4 top and bottem = 8/12 + 1/4 x by 3 top and bottem 3/12 + 8/12 11/12

2/3 = 4/6 1/2 = 3/6 7/6 = 1 1/6 1/3 = 2/6

Subtracting
If it's a mix number make it to a improper fraction first, then find LCD.

Word Problem Tom Anderson set a record when he caught a salmon that weighed 97 1/4 ib. Robert wilson caught a salmon that weighed 74 9/16. How less than the record was this?

97 1/4 - 74 9/16 = 22 11/16