Why is the last condition not satisfied, even though the task is complete?

int secondDigit = tempNum/100; // it rather results the third digit!

public class Solution {
    public static void main(String[] args) {
        System.out.println(sumDigitsInNumber(597));
    }

    public static int sumDigitsInNumber(int number) {
        int sum;
        int tempNum = number / 10 * 10;
        int firstDigit = number - tempNum;
        int secondDigit = tempNum/100;
        System.out.println(secondDigit); // For purpose of test printing
        int thirdDigit = secondDigit -1;


        sum = firstDigit + secondDigit + thirdDigit;

            return sum;

    }

}