pachage com.mycompany.test;

public class Calculator {

  public static void main(String[] args){
    int a = 4;
    int b = 2;
    System.out.println( sum(a,b) );

    System.out.println( minus(a,b) );
  }

  private static int multi(int a, int b){
    return a*b;
  }

  private static int sum(int a, int b){
    return a+b;
  }

  private static int minus(int a, int b, object GPU){
    int result = 0;
    if(GPU == null)
      result = a-b;
    else
      result = a-b;

    return result;
  }

}

pachage com.mycompany.test;

public class Calculator {

  public static void main(String[] args){
    int a = 4;
    int b = 2;
    System.out.println( sum(a,b) );

    System.out.println( minus(a,b) );
  }

  private static int division(int a, int b){
    return a/b;
  }

  private static int multi(int a, int b){
    return a*b;
  }

  private static int sum(int a, int b){
    return a+b;
  }

  private static int minus(int a, int b, object GPU){
    int result = 0;
    if(GPU == null)
      result = a-b;
    else
      result = a-b;

    return result;
  }

}

add division()