Need help with 7-Segment Display

@demonic_crew: code looks good. don't know what you will be doing with it, so I don't know how much reducing can be made.

One simple way to reduce your code could be to create one method to turn off all the leds off. Then you don't have to turn all the LEDs off indivisually each time. Something like this should work (not tested it yet):

void turnLEDoff(){
  digitalWrite(ledPinA, LOW);
  digitalWrite(ledPinB, LOW);
  digitalWrite(ledPinC, LOW);
  digitalWrite(ledPinD, LOW);
  digitalWrite(ledPinE, LOW);
  digitalWrite(ledPinF, LOW);
  digitalWrite(ledPinG, LOW);
  digitalWrite(ledPinRHDP, LOW);
}

Then instead off turning off all the pins as so:

...
  digitalWrite(ledPinA, LOW);         // Turn off 0
  digitalWrite(ledPinB, LOW);
  digitalWrite(ledPinC, LOW);
  digitalWrite(ledPinD, LOW);
  digitalWrite(ledPinE, LOW);
  digitalWrite(ledPinF, LOW);
...

just call the function as so:

turnLEDoff()