Beyond the Eight Trigrams, the Chinese also had another profound and inscrutable diagram: the Luo Shu. China's mathematical system was founded upon the Luo Shu.
The Luo Shu took the form of a nine-square grid. The number five sat in the center, while the other eight numbers occupied the surrounding squares. The eight numbers corresponded to the Eight Trigrams. It was said that Fuxi had drawn it based on the pattern on the back of a divine turtle. As for the Luo Shu, it was supposedly given to Yu by a dragon-horse that appeared in the Luo River.
They noted that the number "five" played an extremely important role in various classifications. For example, the Five Elements were wood, fire, earth, metal, and water. These five numbers could also represent musical notes: gong, shang, jue, zhi, and yu. The earliest guqin had only five strings. Later, King Wen of Zhou added one, and King Wu added another, turning it into a seven-stringed qin.
Two qins together should have made ten strings, yet Zhuangzi said there were twenty-five. Had he calculated incorrectly? Twenty-five would be right if it were multiplication, but why use multiplication here?
The "Nine-Nine Song" had existed at least as early as the Warring States period. Children memorized it as a rhyme, which reminded Nick of his own arithmetic lessons as a student. They had not been happy memories for him.
Both "nine" and "five" represented supreme status. Among them, "five" was regarded as the "Supreme Ultimate," the origin of all things. Thus, "the exalted nine-five" also represented the emperor.
In the I Ching, "five" represented the Hexagram of Waiting. Its sequence explanation stated: "Things in their infancy cannot go without nourishment; waiting is the way of food and drink."
It could be understood as a young child