## 10 April 2018

### How old are you? (version 3)

1. Think of a number from $1$ to $9$.
2. Multiply this number by $9$.
3. Calculate $10$ times your age.
4. From the value obtained in point 3 subtract the value obtained in point 2.
The result is a number of $2$ or $3$ digits. If it has $2$ digits, add them up and get your age. If it has $3$ digits, add the first number that has $2$ digits with the second that has $1$ digit and you also get your age!