private void doOperation(operation curentOp, float curentValue)
        {
            if (PastOperation.Equals(operation.Null))
            {
                Console.WriteLine(Totalizator);

                Totalizator = curentValue;
            }
            else

            if (PastOperation.Equals(operation.Plus))
            {
                Console.WriteLine("initial" + Totalizator);

                Totalizator = Totalizator + curentValue;
                Console.WriteLine("final" + Totalizator);
            }
            else
            if (PastOperation.Equals(operation.Minus))
            {
                Console.WriteLine("initial" + Totalizator);

                Totalizator = Totalizator - curentValue;
                Console.WriteLine("final" + Totalizator);
            }
            else
            if (PastOperation.Equals(operation.Div))
            {
                Console.WriteLine("initial" + Totalizator);

                Totalizator = Totalizator / curentValue;
                Console.WriteLine("final" + Totalizator);
            }
            else
            if (PastOperation.Equals(operation.Prod))
            {
                Console.WriteLine("initial" + Totalizator);

                Totalizator = Totalizator * curentValue;
                Console.WriteLine("final" + Totalizator);
            }

            PastOperation = curentOp;
        }