What is a percent?
A percent (written as
is nothing but a hundredth. This means:
and
and
are just different notations for the same number.
What use has percentage calculation?
Percentage calculation is used to get parts something. Percentage values are just better to read:
looks more ugly than
(but probably just because we are used to reading percentage values). Unfortunately, many people misunderstand the percent sign as something complicated ore a kind of unit. It is not, but it is just a different possibility to write a decimal number with two digits after the decimal sign or a fraction with denominator
:
equal
equal
.
Percentage calculation
If you want to find out what x percent of your number are, divide your number by 100 and multiply it by x.
Example:
How much is 5 percent of 400?
Your exercise:
Given: Base value 400 and percentage 5%. Looking for the percentage value.
Three possible calculations…
First way: Percentage formula
The percentage formula is:  
 ( Idea:  =0,05)
Second way: Rule of three
| 100% | corresponds to | 400 | |
| 1% | corresponds to | 4 | ( Divide both sides by 100 ) |
| 5% | corresponds to | 20 | ( Multiply both sides by 5) |
Third way: Intelligent rule of three
| 100% | corresponds to | 400 | |
| 5% | corresponds to | 20 | ( Divide both sides by 20 ) |
Result:
Base value :400
percentage :20
percentage value :5%
|
What do the phrases base value, percentage and percentage value mean?
The base value is the number given at the start, e.g. an amount of money.
The percentage value is the number standing in front of the percent sign. It says how many percent, i.e. how many hundredth you want.
The percentage is the result of that calculation. If you want to find out what 5 percent of 200 are, the base value is 200, the percentage is 5 and the percentage value is 10.
So this formula holds: Percentage value = base value * (percentage/100).
How to find the base value?
Example:
Mr Smith gets 500 dollars interest, this equals 4%. How much money does he have?
Deine Aufgabe:
Given: Percentage value 500 and percentage 4%. Looking for the base value. G.
Three possible calculations…
First way: Percentage formula
The percentage formula is: Solve the formula for G (i.e. divide both sides by p%):
Second way: Rule of three
| 4% | corresponds to | 500 | |
| 1% | corresponds to | 125 | ( Divide both sides by 4 ) |
| 100% | corresponds to | 12500 | ( Multiply both sides by 100) |
Third way: Intelligent rule of three
| 4% | corresponds to | 500 | |
| 100% | corresponds to | 12500 | ( Multiply both sides by 25) |
Result:
Base value :12500
percentage :500
percentage value :4%
|
How to calculate the percentage value?
Example: A country has 513700 habitants. How many are 3% of them?
Your exercise:
Given: Base value 513700 and percentage 3%. Looking for the percentage value.
Two possible calculations…
First way: Percentage formula
The percentage formula is: 
 ( Idea:  =0,03)
Second way: Rule of three
| 100% | corresponds to | 513700 | |
| 1% | corresponds to | 5137 | ( Divide both sides by 100 ) |
| 3% | corresponds to | 15411 | ( Multiply both sides by 3) |
Result:
Base value :513700
percentage :15411
percentage value :3%
|
How to calculate the percentage?
Example:
In a class there are 24 pupils. 10 of them are girls. What percentage is that?
Your exercise:
Given: Base value 24 and percentage value 10. Looking for the percentage p%
Three possible calculations…
First way: Percentage formula
The percentage formula is: Solve the formula for p (i.e. divide both sides by G):
This means: p% are 41,667%.
Second way: Rule of three
| 100% | corresponds to | 24 | |
| 4,166667% | corresponds to | 1 | ( Divide both sides by 24 ) |
| 41,667% | corresponds to | 10 | ( Multiply both sides by 10) |
Third way: Intelligent rule of three
| 100% | corresponds to | 24 | | 8,333333% | corresponds to | 2 | ( Divide both sides by 12 ) |
| 41.667% | corresponds to | 10 | ( Multiply both sides by 5) |
Result:
Base value :24
percentage :10
percentage value :41,667%
|
Can i see more examples?
Of course. Just enter your exercise above and it will be calculated. Immediately and for free, of course.