# Percentages

The percentage of something is one hundredth of it. That is, 1% = 1/100 = 0,01. The decimal form of a percentage will be used to calculate percentages.

Example 1

1% = 0,01

13% = 0,13

57% = 0,57

100% = 1,00

123% = 1,23

_________________

0,14 = 14%

2,34 = 234%

0,005 = 0,5%

23,00 = 2300%

1,09 = 109%

It is easy to calculate percentages in decimal form. For example, 20% of 50 is 0,2 · 50 = 10. So we multiply the number by a decimal form of percentage.

Example 2

Calculate 7% of 490.

Convert a percentage to a decimal form. 7% = 0.07

0.07 · 490 = 34.3

A percentage equation consists of three parts: the Original value, the Percent coefficient and the Result.

Example 3

Let's calculate how much is 20% of 120.

Original value = 120

Percent coefficient = 0,2

Result = x

The equation is obtained by multiplying the original number by a percentage coefficient equal to the result:

0.2 · 120 = x

24 = x

Calculate 25% of 40?

Original number = x

Percent coefficient = 0,25

Result = 40

Now, we do not know the figure from which 25% has been taken from. So we mark it as unknown by the letter x. However, the equation is formed in exactly the same way.

0,25 · x = 40 || : 0.25

x = 40 / 0,25

x = 160

What percentage is 30 of 270?

Original number = 270 (That is, what we compare to)

Percent coefficient = x

Result = 30 (What we compare)

x · 270 = 30 || : 270

x = 30/270

x ≈ 0.1111 ≈ 0.11 = 11%

Most percentages can be calculated this way. All you have to do is identify the number or value we are starting from, that is, where the percentage is from.

Switch on subtitles if needed