The advantage of this approach is that program only needs one prompt and one read operation.
#include <iostream> using namespace std; int main() { int score; int count = 0; double sum = 0; while (true) { cout << "Enter a score (-1 to end): "; cin >> score; if (score == -1) break; count++; sum += score; } cout << "The average is " << sum / count << endl; return 0; }