Preface from "The Nine Chapters on the Mathematical Art" . . . .
"I studied the Nine Chapters at an early age and perused it when I got older. I see the separation of the Yin and the Yang and arrive at the root of the mathematical art. In this process of probing I comprehend its meaning. Despite ignorance and incompetence on my part I dare expose what I understand in these commentaries. Things are related to each other through logical reasoning so that like branches of a tree, diversified as they are, they nevertheless come out of a single trunk. If elucidated by prose and illustrated by pictures, then we may be able to attain conciseness as well as comprehensiveness, clarity as well as rigour. Looking at a part we will understand the rest."
translated by Prof. Man-Keung SIU, University of Hong Kong
in "How Chinese Learn Mathematics: Perspective From Insiders"
(World Scientific, 2004, Chapter 6)