The letter "A" along with other letters at the beginning of the alphabet are used in algebra to represent known quantities.

One must note that the above definition is somewhat dependent upon our convention of choosing real numbers to represent real physical quantities.

The standard convention of taking the real part of complex quantities to represent physical quantities is used.

The C language provides the separate types and to represent memory-related quantities.

These, in turn, are contained within the real numbers, which are used to represent continuous quantities.

The integer variables represent quantities that can only be integer.

Beyond the smallest units, there was a need to use vulgar fractions to represent even smaller quantities.

Note that if you graph the functions the axes represent quantities.

The publishers embraced the joint venture because it represented vast quantities of free advertising.

It can also be used to represent physical quantities, like torque and angular momentum.