exp10.cpp

int pins[] = {11, 10, 9, 8, 7, 6, 5, 4};

void setup() {
  for (int i = 0; i < 7; i++) {
    pinMode(pins[i], OUTPUT);
  }
}

int number = 0;

void loop()  {
   setNumber();
   delay(1000);
   number = (number + 1) % 10;
}

void setNumber() {
   for (int i = 0; i < 7; i++) {
      if (bitRead(numbers[number], 7 - i) == HIGH) {
         digitalWrite(pins[i], HIGH);
      }
      else {
         digitalWrite(pins[i], LOW);
      }
   }
}

byte numbers[10] = { B11111100,   // 0
                     B01100000,   // 1
                     B11011010,   // 2
                     B11110010,   // 3
                     B01100110,   // 4
                     B10110110,   // 5
                     B10111110,   // 6
                     B11100000,   // 7
                     B11111110,   // 8
                     B11110110    // 9
};