This is dangerous and not very OOPish but you can create an array of Objects and return that. The only danger will be not knowing what comes out on the other side. You will have to cast the data to use it.
Create a class Calculation that performs the calculation and gets returned.
public class Calculation
private double binaryOperand1;
private double binaryOperand2;
private double result;
public Calculation(double op1, double op2)
this.binaryOperand1 = op1;
this.binaryOperand2 = op2;
this.result = null;
//Getters and Setters elided...
public Calculation addOperation()
result = binaryOperand1 + binaryOperand2;
//... and so on