Six copies. The calculation shows that 1 m is equal to 100 cm and 1 cm is equal to 10 mm, that is, 100 divided by 18 is equal to 5.5, which is equivalent to 6 copies. This (pinyin: běn) is a first-class Chinese character (commonly used word) in the General Standard of Chinese. This word first appeared in the bronze inscriptions of the Western Zhou Dynasty, indicating things. The ancient glyph adds an indicator to the lower part of the "wood" to indicate the position of the root. The original meaning refers to roots, and also refers to the stems and trunks of vegetation. It is also a metaphor for fundamental and important things, as opposed to "ending". It also extends to the meaning of subject, origin, origin and origin.