(C language) There is a printf location question when using while.

Hello, I am learning the basics of C language.

Currently, we have completed a coding that outputs several integers and then sums up and averages only a multiple of 3, and escapes by entering -1. I wonder where the printf's while is located inside and outside {}. Some programs function only when you put them inside, and some when you put them outside. (For convenience, include, main, and return were omitted)

It works when you put it inside

int num;
int sum = 0;

while (1) {
scanf_s("%d", &num);
if (num == -1)break;
if (num % 3 != 0) continue;

    sum = num / 3;
    printf("%d\n", sum); } // **Inserted in the WHILE phrase**

It works only when you leave it outside

It's a code that continues to output integers and then escapes when you add an odd sum, average, and enter zero.

 int num;
 int sum = 0, cnt = 0;
 double avg;

while (1) {
scanf_s("%d", &num);
if (num == 0) break;
if (num % 2 != 0) {
sum += num;
cnt++;
}
}
avg = (double)sum / cnt;
printf("sum of odd numbers = %d\n", sum); // **located outside of the WHILE syntax**
printf ("average of odd numbers = %").2lf\n", avg);

No matter how I look at it... It's the same type of coding. Why should one be in while, why should the other be outside while. I don't understand If you're fluent in C, please answer^{^}