// Program: SumArray.ino

void setup () {
  Serial.begin(115200);
}

void loop () {
  int rainfall[] = {4, 2, 8, 6, 20, 12, 7, 5, 2};
  int total = 0;
  float average;
  int size;

  size = sizeof(rainfall) / sizeof(int);

  for (int i = 0; i < size; ++i) {
    total = total + rainfall[i];
  }
  // average = total / size;         //Not ok
  // average = 1.0 * total / size;  //ok
  average = (float) total / size;  //ok

  Serial.print("size = ");
  Serial.println(size);
  Serial.print("Total = ");
  Serial.println(total);
  Serial.print("Average = ");
  Serial.println(average);

  while (1);
}