The decimal comes from Liu Hui in Wei and Jin Dynasties. In the process of calculating pi, he used seven units, such as feet, inches, minutes, centimeters, millimeters, seconds and bumps. For the following units that suddenly become smaller, they are no longer named, and they are collectively called "micro numbers".

During the Song and Yuan Dynasties, the concept of decimal was further popularized and expressed more clearly. Yang Hui's Daily Arithmetic (1262) has a formula for converting two catties: "If you find one, it will be every six or twenty-five; Second, abdicate 125 ",that is,116 = 0.0625; 2/ 16=0. 125。 ?

Here, "separation" and "abdication" already mean the position of decimal point. In Qin dynasty, units are placed under the chip representing integer units. For example,-Ⅲ-Ⅱ means 13. 12 inch is the earliest decimal notation in the world.

Extended data

In English decimal reading, the decimal point is read as "dot", the integer part is read as the basic word, and the decimal part is read separately.

For example: 123. 123, pronounced as: I am hungry at 23.123.

In Europe and Islamic countries, sexagesimal of Babylon has been in a dominant position for a long time, and some classic scientific works have also adopted sexagesimal, so the concept of decimal has never been developed.

/kloc-Alkasi in Central Asia in the 0/5th century (? ~ 1429) is the first person to use decimals outside China.

European mathematicians didn't start to consider decimals until the 6th century/kloc-0, among which the most prominent one was Steven (1548 ~ 1620), who clearly expressed decimals in On Decimal System (1583). For example, record 5.7 14 as: 5 ◎ 7 1 1 243 or 5,7'1'4''.

The first person to express decimals as a universal form in the world today is the German mathematician kravis (1537 ~ 16 12), who began to use decimal points as a separator between integer parts and decimal parts in his book Astral Chart (1593).

Baidu encyclopedia-decimal