The zero, called “nought,” is of course a different thing from the letter O of the alphabet, but there may be a historical connexion between them (§ 79). It is perhaps interesting to note that the latter-day telephone operator calls 1907 “nineteen O seven” instead of “nineteen nought seven.”
14. Direction of the Number-Series.—There is no settled convention as to the direction in which the series of symbols denoting the successive numbers one, two, three, ... is to be written.
(i) If the numbers were written down in succession, they would naturally proceed from left to right, thus:—1, 2, 3, ... This system, however, would require that in passing to “double figures” the figure denoting tens should be written either above or below the figure denoting ones, e.g.
| 1 | ||
| 1, 2, ... 8, 9, | 0, 1, 2, ... or 1, 2, ... , 8, 9, | 0, 1, 2, ... |
| 1 |
The placing of the tens-figure to the left of the ones-figure will not seem natural unless the number-series runs either up or down.
(ii) In writing down any particular number, the successive powers of ten are written from right to left, e.g. 5,462,198 is
| (6) | (5) | (4) | (3) | (2) | (1) | (0) |
| 5 | 4 | 6 | 2 | 1 | 9 | 8 |
the small figures in brackets indicating the successive powers. On the other hand, in writing decimals, the sequence (of negative powers) is from left to right.
(iii) In making out lists, schedules, mathematical tables (e.g. a multiplication-table), statistical tables, &c., the numbers are written vertically downwards. In the case of lists and schedules the numbers are only ordinals; but in the case of mathematical or statistical tables they are usually regarded as cardinals, though, when they represent values of a continuous quantity, they must be regarded as ordinals (§§ 26, 93).
(iv) In graphic representation measurements are usually made upwards; the adoption of this direction resting on certain deeply rooted ideas (§ 23).