Definition: | number in the expression of the value of a quantity, other than any number serving as the reference
NOTE 1 – For quantities that have a unit of measurement (i.e. those other than ordinal quantities), the numerical value {Q} of a quantity Q is frequently denoted {Q} = Q/[Q], where [Q] denotes the unit. For example, for a mass of value expressed as 5,7 kg, the numerical value is {m} = (5,7 kg)/kg = 5,7. The same value can be expressed as 5 700 g in which case the numerical value is {m} = (5 700 g)/g = 5 700.
NOTE 2 – For quantities of dimension one, the reference is a unit of measurement which is a number and this is not considered as a part of the numerical value. For example, in an amount-of-substance fraction equal to 3 mmol/mol, the numerical value is 3 and the unit is mmol/mol. The unit mmol/mol is numerically equal to 0,001, but this number 0,001 is not part of the numerical value, which remains 3.
NOTE 3 – Very often quantities of dimension one are expressed in percent. Example: the volume fraction of alcohol in a very strong beer is 7,2 %.
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