What is a Percentage?

What is a Percentage?

GCSE(F),

Percentage means out of a hundred. To find a percentage, the original quantity is divided up into 100 parts. It is a fraction waiting to happen. A precentage value is shown with a symbol %.

38% is equivalent to `frac(38)(100)`.

Percentages are used to compare values: for example, you might score 45/60 for a maths test, and 63/75 for an English test. Using a percentage marks both scores out of 100: for maths the score is 75%, and for English it is 84%.

Examples

1. The atmosphere of the earth consists of 21% oxygen. Which would be the nearest value as a fraction: `frac(1)(4)`, `frac(1)(2)` or `frac(3)(4)`?

Answer: `frac(1)(4)`

21% is equivalent to `frac(21)(100)`.

`frac(1)(4)` is equivalent to `frac(25)(100)`, so this is the nearest value.

2. A quarter of the pencils in a box of 100 pencils are broken. What percentage is this?

Answer: 25%

A quarter is 25 out of 100. As the value is out of 100, it is 25%