void display()
  {
    System.out.println(  accountNumber + "\t" + accountHolder + 
        "\t" +  balance + "\t" + useCount );
  }
Here is the complete class, including the modified display() method.
class CheckingAccount
{
  // data-declarations
  private String accountNumber;
  private String accountHolder;
  private int    balance;
  private int    useCount = 0;
  //constructors
  CheckingAccount( String accNumber, String holder, int start )
  {
    accountNumber = accNumber ;
    accountHolder = holder ;
    balance       = start ;
  }
  // methods
  private void incrementUse()
  {
    useCount = useCount + 1;
  }
  int getBalance()
  {
    return balance ;
  }
  void  processDeposit( int amount )
  {
    incrementUse();
    balance = balance + amount ; 
  }
  void processCheck( int amount )
  {
    int charge;
    incrementUse();
    if ( balance < 100000 )
      charge = 15; 
    else
      charge = 0;
    balance =  balance - amount - charge  ;
  }
  void display()
  {
    System.out.println(  accountNumber + "\t" + accountHolder + "\t" +  
                         balance + "\t" + useCount );
  }
}
        
What does the useCount keep track of: