1. First of all, pick the number of times a week that you would like to have chocolate (between 1 and 10).
2. Multiply this number by 2.
3. Add 5.
4. Multiply that by 50.
5. If you've already had your birthday this year add 1761. If you haven't, add 1760.
6. Now subtract the four digit year that you were born (1972 etc.)
You should now have a three digit number. The first digit of this was your original number (i.e., how many times you want to have chocolate each week). The next two digits are your age.