2.) 13 - Unlucky for most it's my lucky number
3.) 4 - A word that you shout when you are golfing.
4.) 9.8 - The gravitational constant in meters per second
5.) 3.14159265358979323846264338327950288419716939937510... I know more but I don't feel like typing it - Pi, the comparison of the radius of a circle to the distance around it (it's circumference)