# Percentages (%)

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

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

## Examples:

100% means all.

Example:

 100% of 80 is 100 × 80 = 80 100

50% means half.

Example:

 50% of 80 is 50 × 80 = 40 100

5% means 5/100ths.

Example:

 5% of 80 is 5 × 80 = 4 100

## 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 1 (100% of any number is just the number, unchanged) And 200% is 200/100, or exactly 2 (200% of any number is twice the number) Use the slider on the left side and try some different numbers (What is 40% of 80? What is 10% of 200? What is 90% of 10?)

### A Percent can also be expressed as a Decimal or aFraction

 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
 And 25 × 80 = 20 100

So 25% of 80 is 20

### Example: 15% of 200 apples were bad. How many apples were bad?

 15% = 15 100
 And 15 × 200  =  15 × 200 =  15 × 2  =  30 apples 100 100

### 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
 And 25 × \$120 = \$30 100

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

## The Word

"Percent" comes from the latin Per Centum. The latin word Centum means 100, for example a Century is 100 years.

## Percent vs Percentage

My Dictionary says "Percentage" is the "result obtained by multiplying a quantity by a percent". So 10 percent of 50 apples is 5 apples: the 5 apples is the percentage.

But in practice people use both words the same way.