PERCENTAGES (%)

WHEN WE SAY "PERCENT" WE ARE REALLY SAYING "PER 100"

One percent (1%) means 1 per 100.

1% of this line is shaded green: it is very small isn't it?

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

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

EXAMPLES:

		100% means all. Example: 100% of 80 is 100100 × 80 = 80
		50% means half. Example: 50% of 80 is 50100 × 80 = 40
		5% means 5/100ths. Example: 5% of 80 is 5100 × 80 = 4

USING PERCENT

When 100% =

then:

75% = 60

Use the slider and try some different numbers
(What is 40% of 80? What is 10% of 200? What is 90% of 10?)

BECAUSE "PERCENT" MEANS "PER 100" THINK:

"this should be divided by 100"

So 75% really means 75100

And 100% is 100100, or exactly 1 (100% of any number is just the number, unchanged)

And 200% is 200100, or exactly 2 (200% of any number is twice the number)

A 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

Read more about this at Decimals, Fractions and Percentages.

SOME WORKED EXAMPLES

EXAMPLE: CALCULATE 25% OF 80

25% = 25100

And  25100 × 80 = 20

So 25% of 80 is 20

EXAMPLE: 15% OF 200 APPLES ARE BAD. HOW MANY APPLES ARE BAD?

15% = 15100

30 apples are bad

EXAMPLE: IF ONLY 10 OF THE 200 APPLES ARE BAD, WHAT PERCENT IS THAT?

As a fraction, 10200 = 0.05

As a percentage it is: 10200 x 100 = 5%

5% of those apples are 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% = 25100

And  25100 × $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