NUMERATION, the reading off of numbers that are expressed by figures. As shown in notation (q v.), the first figure on the right hand expresses units; the next, tens; the third, hundreds; and following the same nomenclature with the next three figures, we have the fourth expressing units of thousands; the fifth, tens of thousands; the sixth, hundreds of thousands. The seventh figure..iu like manner, expresses units of millions; the eighth, tens of millions; and the ninth. hundreds of millions. When this method is consistently followed out, as is the case with French and other continental arithmeti cians, the fourth period, or group of three figures, is denominated billions, the first figure of it (the tenth from the extreme right) being units of billions; the next, tens of billions; etc. Read in this way, the figures 56,084,763;204,504 express fifty-six trillions, eighty-four billions, seven-hundred-and-sixty-three millions, two-hundred-and-four thou sands, five-hundred-and-four units. In Britain there is a slight variation in the mode, the only effect of which is to render it a little more complice.ted; thus, after units of
millions, come tens and hundreds of millions, but then instead of billions we have, according to the current usage, thimsands of millions; after this, tens of thousands of millions and hundreds of thousands of millions, and then billions, which occupy the 13th figure from the right, and are reckoned in the same way as milliOns. so that the next •unit or trillions does not come in till the 19th figure. The above number, according to the British mode, would be read fifty-six billions, eiglity-four4housand-seven-hundred and-sixty-three millions, two-hundred-and-four thousands, five-hundred-and four units. The first method is perfectly symmetrical, keeping throughout to divisions of three figures; the second only keeps to this. division up to hundreds of millions, when it changes it for a division into parcels of six figures, which are maned from units up to hundreds of thousands of units. The latter mode is, however, gradually falling into disuse.