To say 1881 they make a complete inversion of our own order, beginning with 1 and ending with 1000.

Their full numeral for this is _yeha av wabki mar-u-wab mar-u-haki_, which means, literally, 1 + 80 + 100 x 8 + 100 x 10.[54] Such exceptions are, however, quite rare.
One other method of combination, that of subtraction, remains to be considered.

Every student of Latin will recall at once the _duodeviginti_, 2 from 20, and _undeviginti_, 1 from 20, which in that language are the regular forms of expression for 18 and 19.

At first they seem decidedly odd; but familiarity soon accustoms one to them, and they cease entirely to attract any special attention.

This principle of subtraction, which, in the formation of numeral words, is quite foreign to the genius of English, is still of such common occurrence in other languages that the Latin examples just given cease to be solitary instances.
The origin of numerals of this class is to be found in the idea of reference, not necessarily to the last, but to the nearest, halting-point in the scale.