PERCENTAGES

Percentages (%)

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

50%So 50% means 50 per 100
(50% of this box is green)
And 25% means 25 per 100
(25% of this box is green)
25%


Examples:

100%
100% means all.
Example:
100% of 80 is 100/100 × 80 = 80
50%
50% means half.
Example:
50% of 80 is 50/100 × 80 = 40
5%
5% means 5/100ths.
Example:
5% of 80 is 5/100 × 80 = 4

Using Percent

Because "Percent" means "per 100" think:
"this should be divided by 100"
So 75% really means 75/100
And 100% is 100/100, or exactly (100% of any number is just the number, unchanged)
And 200% is 200/100, or exactly (200% of any number is twice the number)
Use the slider on the left and try some different numbers (example, what is 40% of 80?)

Percent can also be expressed as a Decimal or a Fraction


A Half can be written...
As a percentage:
50%
As a decimal:
0.5
As a fraction:
1/2

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

S-BATCH