For example: In many European languages there are two principal systems, taken from Latin and Greek, each with several subsystems; in addition, Sanskrit occupies a marginal position.
[B] There is also an international set of metric prefixes, which are used in the world's standard measurement system.
Enumeration with the distributive category originally was meant to specify one each, two each or one by one, two by two, etc., giving how many items of each type are desired or had been found, although distinct word forms for that meaning are now mostly lost.
For the hundreds, there are competing forms: Those in -gent-, from the original Latin, and those in -cent-, derived from centi-, etc.
This is not an absolute rule, however, and there are exceptions (for example: quarter-deck occurs in addition to quarterdeck).
In certain classes of systematic names, there are a few other exceptions to the rule of using Greek-derived numerical prefixes.