private String hundredsPart(int number){
        StringBuffer buffer = new StringBuffer();
        if(number != 0){
            if(number <= 99){
                buffer.append(tenthPart(number));
            }else{
                int first = (number /100);
                int second = number % 100;
                buffer.append(toString(first) + toString(100));
                if (second != 0){
                    buffer.append(tenthPart(second));
                }
            }
            return buffer.toString();
        }else{
            return "";
        }
    }
Convert a number into words

Reference
https://leetcode.com/problems/integer-to-english-words/
src/com/interview/misc/NumberToWord.java