When you say "Percent" you are really saying "per 100"

So 50% means 50 per 100 
And 25% means 25 per 100 


Examples:

100% means all. Example: 100% of 80 is ^{100}/_{100} × 80 = 80 


50% means half. Example: 50% of 80 is ^{50}/_{100} × 80 = 40 


5% means ^{5}/_{100ths}. Example: 5% of 80 is ^{5}/_{100} × 80 = 4 
A Percent can also be expressed as a Decimal or a Fraction


Some Worked Examples
Example: Calculate 25% of 80
25% = ^{25}/_{100}
(^{25}/_{100}) × 80 = 20
So 25% of 80 is 20
Example: 15% of 200 apples were bad. How many apples were bad?
15% = ^{15}/_{100}
(^{15}/_{100}) × 200 = 15 × 2 = 30 apples
30 apples were bad
Example: if only 10 of the 200 apples were bad, what percent is that?
As a fraction, 10/200 = 0.05
As a percentage it is: (10/200) x 100 = 5%
5% of those apples were bad
Example: A Skateboard is reduced 25% in price in a sale. The old price was $120. Find the new price
First, find 25% of $120:
25% = ^{25}/_{100}
(^{25}/_{100}) × $120 = $30
25% of $120 is $30
So the reduction is $30
Take the reduction from the original price
$120  $30 = $90
The Price of the Skateboard in the sale is $90