Basic math
all you are doing is subtracting the year you were born from 2008 or 2009 (5*50 = 250 +1758/1759 = 2008/2009.... whether youve had your bday or not), and putting the number you pick in front of it by multiplying it by 100 (2*50)
I hate being such a nerd that I can't fall for these
