If it be even, the even number is in the right hand; but if it be odd, the even number is in the left hand.
| Example I. | ||
| No. in right hand. | No. in left hand. | |
| 18 | 7 | |
| 3 | 2 | |
| — | — | |
| 54 | 54 | 14 |
| 14 | ||
| — | ||
| 68 sum of the products. | ||
| Example II. | ||
| No. in right hand. | No. in left hand. | |
| 7 | 18 | |
| 3 | 2 | |
| — | — | |
| 21 | 36 | 36 |
| 21 | ||
| — | ||
| 57 sum of the products. | ||
A Person having fixed on a Number in his Mind, to tell him what Number it is.
Bid him quadruple the number thought on, or multiply it by 4; and having done this, desire him to add 6, 8, 10, or any even number you please, to the product; then let him take the half of this sum, and tell you how much it is; from which, if you take away half the number you desired him at first to add to it, there will remain the double of the number thought on.
Example.
| Suppose the number thought on is | 5 | ||
| The quadruple of it is | 20 | ||
| 8 added to the product is | 28 | ||
| And the half of this sum | 14 | ||
| 4 taken from this leaves | 10. | — |
Therefore 5 was the number thought on.
Another Method of discovering a Number thought on.