But the origin of decimal point existed in China during the Southern Song Dynasty!
Qin (A.D. 1202 ~ 12 1), a mathematician in the Southern Song Dynasty, wrote eighteen volumes of Shu Shu Jiu Zhang in 1247 (the seventh year of Chunyou). There are ***8 1 topics in the book, which are divided into nine categories: big research and Juyi. This is an epoch-making masterpiece, which summarizes the methods used by predecessors in square root and applies them flexibly and systematically to solve the rational or irrational roots of higher-order equations. Among them, the "first congruence group solution" and "positive and negative square root solution" (numerical solution of higher order equations) are deeply studied. Among them, "one-time congruence group solution" occupies a lofty position in the history of world mathematics. In ancient times, there was a problem of "uncountable things" in the Art of War. For example, there is a number, three or three numbers make up two, five or five numbers make up two, and seven or seven numbers make up two. Why this number? The solution of this kind of problem can be extended to the general method of solving linear congruence groups. Jiu Shao gave a theoretical proof, and named it "Da Yan Qiu Shu".
Qin (the date of birth and death is unknown, and the active period is about13rd century), a mathematician from China in the Southern Song Dynasty, was born in Sichuan, and he wrote Shu Shu Jiu Zhang (1247)18. There is a deep study on finding a number by the method of big derivative (a solution of congruence in integer theory) and "extraction of positive and negative roots" (a method of finding the positive roots of digital high-power processes). China has used decimal counting method since ancient times, and some practical units of measurement also use decimal, so it is easy to produce the concept of decimal. The first person to express this concept in words was 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, you will find it every six or twenty-five; Second, abdicate 125 ",that is,116 = 00625; 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. 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).