Using a calculator with this puzzle might help
Take the number of the month you were born,
multiply by 4,
add 13,
multiply by 25, subtract 200,
add the day of the month on which you were born,
multiply by 2, subtract 40, multiply by 50, add the last two digits of the year in which you were born,
subtract 10,500.
Notice anything funny about your answer?
Did your math teacher teach you this?