You are setting values for operand1 and operand2 for ops object but not result object.
MathOperations ops = new MathOperations();
Console.WriteLine("Enter first number to calculate");
ops.Operand1 = int.Parse(Console.ReadLine());
Console.WriteLine("\nEnter second number to calculate");
ops.Operand2 = int.Parse(Console.ReadLine());
but calling methods on result object whose operand1 and operand2 are initialized to 0 and hence the return values of functions. Remember ops' operand1 and operand2 hold user's input, not result's operand1 and operand2. You should use same ops object for result calculation.