private void drawNumberInsideCardArea(Graphics g, Card aFaceDownCard) {  
    Rectangle cardArea = aFaceDownCard.getCardArea();
    int numberLeftInPack = cardStack.size();
    g.setFont(new Font("Times", Font.BOLD, 48));
    if (numberLeftInPack < 10) {
      g.drawString("" + numberLeftInPack, cardArea.x + cardArea.width / 3, cardArea.y + cardArea.height * 2 / 3);   
    } else {
      g.drawString("" + numberLeftInPack, cardArea.x + cardArea.width / 8, cardArea.y + cardArea.height * 2 / 3);   
    }
  }