Both the methods described above are found in all parts of the world, but what I have called the direct is far more common than the other. In general, where the smaller number precedes the larger it signifies multiplication instead of addition. Thus, when we say "thirty," _i.e._ three-ten, we mean 3 x 10; just as "three hundred" means 3 x 100. When the larger precedes the smaller, we must usually understand addition. But to both these rules there are very many exceptions. Among higher numbers the inverse order is very rarely used; though even here an occasional exception is found. The Taensa Indians, for example, place the smaller numbers before the larger, no matter how far their scale may extend. 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.