Divisibility


 * **Divisible by** ||
 * 2 || -- last digit is even -- 0, 2, 4, 6, or 8. ||
 * 3 || -- sum of the digits is divisible by 3. ||
 * 4 || -- last two digits divisible by 4. ||
 * 5 || -- last digit is a 0 or a 5. ||
 * 6 || -- divisible by both 2 and 3. ||
 * 7 || -- (the number created by all but the ones digit) - 2 x (ones digit) is divisible by 7. ||
 * 8 || -- last 3 digits divisible by 8. ||
 * 9 || -- sum of the digits is divisible by 9. ||
 * 10 || -- last digit is 0. ||