The follwoing is an example of a function which was created to
be a re-useable module. It can be used many times over to sum a sequence of
numbers (from 0 to num) without writing the same code over and over.
int Sum10 (int num) {
int answer, i;
answer = 0;
for ( i = 0; i <= num; i++ ) {
answer += i;
}
return (answer);
}