Arithmetic.
Notation and numeration.
§ 1. In writing numbers ten figures are used. They are the following:—
| 1 | called | One, |
| 2 | “ | Two, |
| 3 | “ | Three, |
| 4 | “ | Four, |
| 5 | “ | Five, |
| 6 | “ | Six, |
| 7 | “ | Seven, |
| 8 | “ | Eight, |
| 9 | “ | Nine, |
| 0 | which is called a cipher, or | Naught. |
One is called a unit. Each of the first nine figures express
a certain number of units. Naught (0) means nothing, or none.
Thus, if you wish to show that there are no apples in a
basket, you can write thus:—The number of apples in the
basket is, 0.
§ 2. The number ten is expressed by writing naught on the right hand of one, thus:—10. This reads, ten.
Here 1 stands for the number of tens written, and the naught shows that there are no units, or ones, here written.
To express eleven, you write thus:—11. Here is 1 in the unit’s place, and 1 in the ten’s place. This shows that there is one unit and one ten written.
To express twelve, you write thus:—12. Here is 2 in the unit’s place, and 1 in the ten’s place. This shows that there are written two units and one ten.
Thus we see that units are written in the first place, reckoning from the right hand, and tens are written in the second place; thus:—
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