Dictionary · Standards & Units
Quantity calculus
The set of mathematical rules applied to quantities rather than bare numbers — the algebra by which units propagate through equations.
Related terms
More from Standards & Units
Numerical value equation
A relation between numerical values that holds only for stated units — the form most spreadsheet formulas quietly are, and the reason unit discipline matters.
VIM (JCGM 200:2012) 1.25
Coherent derived unit
A derived unit that is a product of powers of base units with no numerical factor other than one — the newton is coherent in the SI; the kilometre per hour is not.
VIM (JCGM 200:2012) 1.12
Quantity
A property of a phenomenon, body, or substance to which a magnitude can be assigned and expressed as a number and a reference (typically a measurement unit).
VIM (JCGM 200:2012) 1.1
International measurement standard
A standard recognized by signatories to an international agreement and intended to serve worldwide.
VIM (JCGM 200:2012) 5.2
System of quantities
A set of quantities together with the non-contradictory equations relating them — the framework a system of units is built on.
VIM (JCGM 200:2012) 1.3
Quantity-value scale
The ordered set of values that quantities of a given kind may take — the scale a thermometer or hardness tester reports on.
VIM (JCGM 200:2012) 1.27