//Sorry I'm not sure what Code tags are, but this is the code. Pretty much copy-paste from the template.
const int numReadings = 100;
int readings[numReadings];
int readIndex = 0;
int total = 0;
int average = 0;
int inputPin = A0;
void setup() {
Serial.begin(9600);
for (int thisReading = 0; thisReading < numReadings; thisReading++) {
readings[thisReading] = 0;
}
}
void loop() {
total = total - readings[readIndex];
readings[readIndex] = analogRead(inputPin);
total = total + readings[readIndex];
readIndex = readIndex + 1;
if (readIndex >= numReadings) {
readIndex = 0;
}
average = total / numReadings;
Serial.println(average);
delay(100);
}