219
- = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( )
% < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9
( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8
9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7
8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6
7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5
6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3
WHAT IS A PERCENTAGE?
Percentages are important. We are always meeting up with them
whether we like them or not. Percentages are used in most sporting
competitions. Th e percent sign looks like this: %.
Stores off er sales with 20% off. Taxes are quoted in percentages. We
are told there is a 6% surcharge on certain items. Most people are
happy to let somebody else calculate the amount for them, and they
simply take the person’s word for what they pay.
Often we need to calculate what we will have to pay beforehand—
we need to be able to calculate percentages for ourselves.
Percentages are really fractions: “per cent” actually means “for every
hundred.” So 50% means 50 for every 100, or ⁄. You can see
that 50 and 100 are both divisible by 50. Fifty divides once into 50
and twice into 100. So 50% is the same as ⁄ or ½. It makes sense
that 50 is half of 100.
P PERCENTAGESERCENTAGES
AAppendix Gppendix G
bbapp07.indd 219app 07 .indd 219 1 1/9/07 8:43:03 AM/ 9 / 07 8 : 43 : 03 AM
- = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( )