九章算術
The word "Jiu", or "9", means more than just a digit in ancient Chinese. In fact, since it is the largest digit, it often refers to something of a grand scale or a supreme authority. Further, the word "Zhang", or "Chapter", also has more connotations than simply being the "chapter". It may refer to a section, several parts of an article, or an entire treatise. Given these historical understanding of ancient Chinese, the book "The Nine Chapters on the Mathematical Art" is actually a somewhat mistranslation; it should really mean a grand book for mathematics.