It is necessary for overseas students to learn some relevant cultural knowledge about China when the learn Chinese in China because it plays a crucial role in Chinese language. In China, number can carry very important information of the culture, among which nine is very special.
In the traditional culture of Chinese nation, the number “9” is the biggest of the odd numbers as well as the biggest of the single digit. Students learn Mandarin should know that it is this reason that it is called “天数”, meaning the number of the heaven.
As it became a sacred number, many things about the emperors are related to the number “9”. Let me take some examples for students study in China to prove this. The emperors in the ancient China were called “九五之尊”. The size of the palaces and buildings related to the emperors are all based on the unit “9”. The gates of the Forbidden City and the imperial gardens are decorated with the nine spikes. In each gate, nine spikes are used in vertical and nine in horizontal, altogether they are 81 spikes.
What’s more, the height of the halls in the imperial palace are all nine Zhang and nine Chi, with the same height as the Zhengyang Gate and the Paiyun Hall of the Summer Palace. Besides, students study Chinese may not know that the diameter of the top story of the Temple of Heaven is also nine Zhang and nine Chi. There also a cypress named “九龙柏”.
In Qing Dynasty, the rajahs of the Mongolia presented eight white horses and one white camel as tribute to the emperor, calling it “九白之贡”. For the other tributes, all were calculated with nine or the multiples of nine. If you go to school to study Mandarin, the teacher may tell you that even the implements in the emperor palace are all named with “9” such as “九龙杯”, “九龙壶”, “九龙柱”, etc.
As a numeral, “9” was both definite number and imaginary number in ancient China. So students learn Chinese language should know the usage of the definite number and the imaginary number. When it functioned as the imaginary number, it means “many” and often more than nine. For instance, the set phrase “九转回肠”, it not means the gut turn around for nine times, but to indicate that people are troubled in thoughts.
In Chinese people’s notion about the number, “九” is the biggest and the most. Let me take some specific examples to explain this. The “九” in “九牛一毛” and “九死一生” is used to imply that there are very much or many of something. However, the “九” in “九五之尊”, “九霄凌云” and “九重天” is to express the biggest or most or the extreme of something. In this level, teachers often teach Mandarin language by the examples illustrated above.
For the purpose of describing the degree of big and many, Chinese people in ancient time were fond of multiplying the number of nine. They can double nine into eighteen, quadruple into thirty-six, eight times into seventy-two, etc. here are some typical examples often listed in Mandarin learning courses: 十八罗汉、十八般武艺；三十六计、三十六行、三十六天罡；七十二地煞、孔夫子七十二弟子、孙悟空七十二变；一百零八将、新年寺院撞钟要一百零八下, etc.
When we study Mandarin in Chinese language school, we often see the character “玖”, which is the capital form of the Chinese numeral “九”. The original meaning of this character was a kind of beautiful black stone just secondary to the jade. After the Emperor Wu Zetian in power, she borrowed it as the capital form of nine because of the same pronunciation.
About the number “9” in China, the most important point is that it was the symbol of the emperors because it was regarded as a sacred number. You can learn more about it in the Mandarin language courses in China if you are interested in it.
After learning the most important number in China, Chinese language learners can know more about theChinese culture, thus in turn promoting the Chinese language learning.