3 Digit Arduino Binary Counter

//3 Digit Arduino Binary Counter
//Counter 1-999
#define A 2
#define B 3
#define C 4
#define D 5
// Pins driving common anodes
#define CA1 6
#define CA2 7
#define CA3 8
// Pins for A, B, C, D in sequence
const int segs[4] = {2, 3, 4, 5};
// Segments that make each number
const byte numbers[10] = {0b1111, 0b1110, 0B1101, 0b1100, 0b1011, 0b1010, 0b1001, 0b1000, 0b0111, 0b0110};
 void setup() {
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);
}
void loop() {
  for (int digit1=0; digit1 < 10; digit1++) {
    for (int digit2=0; digit2 < 10; digit2++) {
      for(int digit3=0; digit3 < 10; digit3++) {
      unsigned long startTime = millis();
      for (unsigned long elapsed=0; elapsed < 600; elapsed = millis() - startTime) {
        lightDigit1(numbers[digit1]);
        delay(5);
        lightDigit2(numbers[digit2]);
        delay(5);
        lightDigit3(numbers[digit3]);
        delay(5);

      }
    }
  }
}
}
void lightDigit1(byte number) {
  digitalWrite(CA1, LOW);
  digitalWrite(CA2, LOW);
  digitalWrite(CA3, HIGH);
  lightSegments(number);
}
void lightDigit2(byte number) {
  digitalWrite(CA1, LOW);
  digitalWrite(CA2, HIGH);
  digitalWrite(CA3, LOW);
  lightSegments(number);
}
void lightDigit3(byte number) {
  digitalWrite(CA1, HIGH);
  digitalWrite(CA2, LOW);
  digitalWrite(CA3, LOW);
  lightSegments(number);
}

void lightSegments(byte number) {
  for (int i = 0; i < 4; i++) {
    int bit = bitRead(number, i);
    digitalWrite(segs[i], bit);
  }
}