private static String convertFromAnotherDecades(final char[] digits) {
        final String start;

        switch (digits[0]) {
            //case '1' : start = "one"; break;
            case '2' : start = "twenty"; break;
            case '3' : start = "thirty"; break;
            case '4' : start = "forty"; break;
            case '5' : start = "fifty"; break;
            case '6' : start = "sixty"; break;
            case '7' : start = "seventy"; break;
            case '8' : start = "eighty"; break;
            case '9' : start = "ninety"; break;
            default : start =  "";
        }

        final String end = convertOneDigit(digits[1]);

        return start + end;
    }