Well, I'd certainly use Frogleg's method in practice but I think what you're supposed to do is something like this which (as you surmised) does involve repeated division by 10 and finding the remainder:
using System;
class Program
{
static void Main()
{
int number = 0;
while(true)
{
Console.Write("Please enter a five digit number or q to quit : ");
string input = Console.ReadLine();
if(input.Length > 0 && input.ToLower()[0] == 'q')
{
return;
}
else if(input.Length != 5)
{
Console.WriteLine("Needs to be exactly five digits");
}
else if(!int.TryParse(input, out number))
{
Console.WriteLine("Not a valid number");
}
else
{
bool isPalindrome = IsPalindrome(number);
if (isPalindrome)
Console.WriteLine("{0:D5} is a palindrome", number);
else
Console.WriteLine("{0:D5} is not a palindrome", number);
Console.WriteLine();
}
}
}
static bool IsPalindrome(int number)
{
int[] digits = new int[5];
int index = 4;
while(index >= 0)
{
digits[index] = number % 10;
number /= 10;
index--;
}
if (digits[0] == digits[4] && digits[1] == digits[3]) return true;
return false;
}
}