Math.random() return wrong values and can't figure out why

I've got an assignment in JAVA that is a card game like War. I have to set values for 1-13 to signify cards and pick them at random. I've declared my variables and set them to have a max value, but I still get values that are well over 13. I've used Math.random() many times before with no problems whatsoever. I haven't condensed the code and probably some bloated lines and other lines just need not be there but it shouldn't affect my Math.random() numbers. Any help is greatly appreciated!!

class Card {

   public int cardNum;
   public int cardSuit1;
   public int cardSuit2;
   public final int CARDS_IN_SUIT;

     public Card() 
    {
        this.CARDS_IN_SUIT = 13;
        this.cardSuit1 = 4;
        this.cardSuit2 =4;
    }
     public void setCardNum1(int card)
   {
      cardNum = card;
   }
     public int getCardNum1()
   {
       if ((cardNum > 13) || (cardNum < 1))
       {
         cardNum = (((int) (Math.random() * 100 % CARDS_IN_SUIT + 1)));
       }
      return cardNum;
   }

     public void setCardNum2(int card)
   {
      cardNum = card;
   }
     public int getCardNum2()
   {
      cardNum = (((int) (Math.random() * 100 % CARDS_IN_SUIT + 1)));
      return cardNum;
   }

   public int setCardSuit1()
   {
       cardSuit1 = ((int) (Math.random() * 100 % cardSuit1 + 1));

      switch (cardSuit1)
      {
            case 1:
              Integer.parseInt("Spades");
              break;
            case 2:
              Integer.parseInt("Hearts");
              break;
            case 3:
              Integer.parseInt("Diamonds");
              break;
            case 4:
              Integer.parseInt("Clubs");
              break;
      }       
      return cardSuit1;
   }
     public int getCardSuit1()
   {
     return cardSuit1;
   }

     public int setCardSuit2()
    {   
      cardSuit2 = ((int) (Math.random() * 100 % cardSuit2 + 1));

      if (cardSuit1 == cardSuit2)
      {
       cardSuit2 = ((int) (Math.random() * 100 % cardSuit2 + 1));
      }
      else
      {
          return cardSuit2;
      }

      switch (cardSuit2)
      {
            case 1:
                Integer.parseInt("Spades"); 
                break;
            case 2:
                Integer.parseInt("Hearts");    
                break;
            case 3:
                Integer.parseInt("Diamonds");    
                break;
            case 4:
                Integer.parseInt("Clubs");
                break;
       } 
      return cardSuit2;
}
   public int getCardSuit2()
   {
      return cardSuit2;
   }

}

/////////////////////////////////////////////////////////////////////////

import javax.swing.JOptionPane;
class DisplayCard      
{

   public static void main(String[] args)
   {
       final int CARDS_IN_SUIT = 13;
       final int cardNum = (((int) (Math.random() * 100 % CARDS_IN_SUIT + 1))); 
       Card firstCard = new Card();
       Card secondCard = new Card();
       firstCard.setCardNum1(cardNum);
       firstCard.getCardSuit1();
       secondCard.setCardNum2(cardNum);
       secondCard.getCardSuit2();
       JOptionPane.showMessageDialog(null, "Your first card is the " +
         firstCard.getCardNum1() + firstCard.getCardSuit1() + " and the second"
               + " card for your hand is " +
               secondCard.getCardNum2() + secondCard.getCardSuit2());
   }
}