PrimeNumbers

    // A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself. The smallest prime number is 2, since its only divisors are 1 and 2.
    // The prime number at position 1 is: 2
    // http://www.geocachingtoolbox.com/index.php?page=primeNumbers

            Console.WriteLine("Prime numbers:");
            bool isPrime = true;
            for (i = 2; i < 100; i++)
            {
                isPrime = true;
                for (int j = 2; j < i; j++)
                {
                    // if (i % j == 0)
                    if (i % Math.Sqrt(j) == 0) // better
                    {
                        isPrime = false;
                        break;
                    }
                }
                if (isPrime) {
                    Console.WriteLine(i);
                }
            }