# Percentages » Percentages using ratio tables

To calculate from numbers to percentages and vice versa you can follow these steps:

1. | Make a ratio table with the amount at the top and the percentages at the bottom. |

2. | Write all the useful numbers that are given in the table. Underneath the total you always write 100%. |

3. | Find out what you need to do to get to your answer. Calculate using 1! |

4. | Calculate the percentage or the unknown number. |

Below you can find two examples. In the first the percentage is calculated and in the second the amount is calculated.

*Example 1*

If you get a reduction of 369 euros on a washing machine of 1230 euros, what percentage is the reduction?

: 1230 |
× 369 |
|||||

euros |
1230 | 1 | 369 | |||

percentage |
100 | ... | 30 | |||

: 1230 |
× 369 |
|||||

Calculation: 100 : 1230 × 369 = 30%

*Example 2*

How many cars are yellow when 12% of the 25 cars are yellow?

:100 |
×12 |
|||||

number of cars |
25 | ... | 3 | |||

percentage |
100 | 1 | 12 | |||

:100 |
×12 |
|||||

Calculation: 25 : 100 × 8 = 3 yellow cars

*Example 3*

A tv costs 484 euros including 21% VAT. What is the cost of the tv excluding VAT?

:121 |
×100 |
|||||

euros |
484 | ... | 400 | |||

percentage |
121 | 1 | 100 | |||

:121 |
×100 |
|||||

Calculation: 484 : 121 × 100 = 400 euros