Quite neat little trick:
Pick any number between 1 and 100,000 (maybe the last four or five digits of your phone number).
Multiply it by 2.
Add 5.
Multiply the answer by 50.
If you have already had your birthday this year add 1758, if not add 1757*.
Subtract the four digit year that you were born.
You should see now your original number followed by your age.
*1758 and 1757 work for the year 2008. Add 1 for each year after this, for example in 2009 use 1759 and 1758.
Pick any number between 1 and 100,000 (maybe the last four or five digits of your phone number).
Multiply it by 2.
Add 5.
Multiply the answer by 50.
If you have already had your birthday this year add 1758, if not add 1757*.
Subtract the four digit year that you were born.
You should see now your original number followed by your age.
*1758 and 1757 work for the year 2008. Add 1 for each year after this, for example in 2009 use 1759 and 1758.