Principal

public class principal3 {



    public static void main(String[] args) {

         int op = 0,res;

         operaciones3 ej = new operaciones3();

        op= ej.PedirOp();
        ej.PregNumeros();

        switch(op){
        case 1:
            System.out.println(res= ej.suma());
            break;
        case 2:
            System.out.println(res= ej.resta());
            break;
        case 3:
            System.out.println(res= ej.division());
            break;
        case 4:
            System.out.println(res= ej.multiplicacion());
            break;
        default:

            break;
        }
    }
}