Fractions

Fractions

1. Multiplying Fractions

   • cancel down by dividing the top and bottom by any common factor in either fraction
     • now multiply the top and bottom numbers seperately
   • find 8/15 x 5/12
     • 8 and 12 both divide by 4
     • 15 x 5 both divide by 5
       • = 2/3 x 1/3 = 2x1/3x3 = 2/9

2. Dividing fractions

   • rewrite the mixed numbers as fractions
     • Turn 7/2 upside down and multiply
       • simplify by cancelling the 7s
   • 2 1/3 divided by 3 1/2
     • = 7/3 divided by 7/2
       • 7/3 x 2/7
         • 1/3 x 2/1 = 2/3

3. Adding/ subracting Fractions

   • make sure the denominators are the same
     • add/ subtract the top lines only
   • 11/5 + 3/2
     • 11 + 3 = 14
       • 7/14 = 1/2
     • 5 + 2 = 7
   • 11/5 - 3/2
     • 22/10 - 15/10
       • 22- 15/10
         • 7/10