private String GetDoubleDigitWord(int number) {
        switch (number) {
            case 20:
                return "twenty";
            case 30:
                return "thirty";
            case 40:
                return "forty";
            case 50:
                return "fifty";
            case 60:
                return "sixty";
            case 70:
                return "seventy";
            case 80:
                return "eighty";
            case 90:
                return "ninety";
        }
        return "";
    }