Calculate the GPA

Why is my average estimate wrong?

I have a function:

int student_average_scope() {
  char name[50];
  int group;
  int exam;
  int average = 0;
  int digit = 0;
  int counter_digits = 0;

  for (int i = 0; i < 4; i++) {
    sscanf(student_list[i], "%d %[^0-9] %d", &group, name, &exam);

    while (exam > 0) {
      digit = exam % 10;
      average += digit;
      counter_digits++;
      exam = exam / 10;
    }

    printf("%.1f\n", (double)average / counter_digits);
  }

  return 0;
}

      

        
        
        
      

    

Where the student_list[i] = "4273 . . 4333 "

average is 3.9, but the correct answer is 3.2! And if I do a simple function, calculate the GPA, give me the correct result (3.2). Where did I go wrong?

int student_average_scope() {
    int exam = "4333";

    int average = 0;
    int digit = 0;
    int counter_digits = 0;

    while (exam > 0) {
        digit = exam % 10;
        average += digit;
        counter_digits++;
        exam = exam / 10;
    }

    printf ("%.1f\n", (double) average / counter_digits);

    return 0;
}