[Tutor] help with prime number program

[Norman Silverstone]

> I am trying to write a program that will figure out if a number is prime
> or not. Currently this is the code that I have:
> 
> import math
> 
> def main():
> 
>     number=input("Please enter a positive whole number greater than 2: ")
>     for value in range(2, number-math.sqrt):
>         if number % value == 0:
>             print number, "is not prime"
>             exit
>     print number, "is prime"
> 
> main()

I am a beginner so, I hope what I give, makes sense. In it's simplest
form what is wrong with :-

n = input("Enter a number")
if n % 2 != 0 and n % 3 != 0:
   print n, " Is a prime number"

Comments please.

Norman