Fractions Made Easy 181
Test you rself
Try these for yourself (do them in your head):
a)^1 /^4 –^1 /^5 =
b)^1 / 2 –^1 / 6 =
c)^1 / 4 –^1 / 7 =
d)^1 / 3 –^1 / 7 =
The answers are:
a)^1 /^20 b)^1 /^3 c)^3 /^28 d)^4 /^21
Can you believe that adding and subtracting fractions could be so
easy?
MULTIPLYING FRACTIONS
What answer would you expect if you had to multiply one-half by
two? You would have two halves. How about multiplying a third by
three? You would have three thirds. How much is two halves? How
much is three thirds?
If you split something into halves and bring the two halves together,
how much have you got? A whole. You could say it mathematically
like this: ½ × 2 = 1.
If you cut a pie into thirds, and you have all three thirds, you have
the whole pie. You could say it mathematically like this: ⅓ × 3 = 1.
Here is another question: what is half of 12? Th e answer is obviously
- But, what did you do to fi nd your answer? To fi nd half of a number,
you divide by 2. Or, you could say, you multiplied by one-half. If
you can understand that, you can multiply fractions.
cc18.indd Sec1:181 18 .indd Sec 1 : 181 1/9/07 8:40:37 AM 1 / 9 / 07 8 : 40 : 37 AM
