per cent

The per cent may be in general interpreted to mean a ‘hundredth’. So e.g. 5 per cent is ‘5 hundredths’, i.e. 5100.

In practice, giving some number of per cents, one means so many hundredths of a quantity given in the same or being clear from the context; for example, we can say that the illiteracy in the world is about 20 per cent – meaning that 20/100 of the adults of the world cannot read. If we say that the interest (rate) of a loan is 8 per cent, it means that one must pay interest for the loan 8/100 of the amount of the loan in a year.

If a percentage of a quantity has changed e.g. from 12% to 15%, we must not say that it has grown 3% but that it has grown 3 percentage points.

Determination of percentage

How many percent a number a is of a second number b? The answer, the per cent number p, is obtained from

p=ab100. (1)

The number b here is called the base value and a the per cent value(?). Essentially, the procedure in (1) may be replaced by converting the ratio ab to hundredths, which can be done formally by multiplying this ratio by  1=100100=100%:

Title per cent
Canonical name PerCent
Date of creation 2013-03-22 17:32:43
Last modified on 2013-03-22 17:32:43
Owner CWoo (3771)
Last modified by CWoo (3771)
Numerical id 7
Author CWoo (3771)
Entry type Definition
Classification msc 97D99
Classification msc 00A69
Synonym percent
Defines percentage point
Defines per cent number
Defines base value
Defines per cent value