number in the expression of a quantity value, other than any number serving as the reference
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NOTE 1 For quantities of dimension one, the reference is a measurement unit which is a number and this is not considered as a part of the numerical quantity value.
EXAMPLE In an amount-of-substance fraction equal to 3 mmol/mol, the numerical quantity 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 quantity value, which remains 3.
NOTE 2 For quantities that have a measurement unit (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 measurement unit.
EXAMPLE For a quantity value of 5.7 kg, the numerical quantity value is {m} = (5.7 kg)/kg = 5.7. The same quantity value can be expressed as 5 700 g in which case the numerical quantity value {m} = (5 700 g)/g = 5 700.