📖Definition
Percentages, fractions and decimals are simply different ways of expressing the same thing.
A Percentage is shown by the % sign. This simply means 'out of 100'. So, 21% means 21 out of 100.
Another way of putting this is 21/100.
That is, a percentage is really a fraction with a denominator of 100.
Method
It's quite easy to convert between percentages, fractions and decimals. Look at the table to see how.
Diagram
💡Tips/hints
It's worth remembering the simpler conversions so that you can do them without having to think - it'll save time in the exam.
Diagram
✏️Example
What percentage of this shape is shaded green?
Diagram
✅Solution
The square is split into 4 equal parts, 3 of which are shaded green,
As a fraction, that's 3/4.
We need to convert this into a percentage.
To do this we multiply the numerator by 100 and divide by the denominator.
So, as a percentage, it's (3 x 100) ÷ 4 = 300 ÷ 4 = 75%.