Desire a person to think of a number--say 6. He must then proceed as
follows:
EXAMPLE.
1. Add 1 to it 7
2. Multiply by 3 21
3. Add 1 again 22
4. Add the number thought of 28
Let him tell you the figures produced 28
5. You then subtract 4 from it 24
6. And divide by 4 6
Which you can say is the number he thought of.