In the development of human society there is a need to measure the length, area, weight, etc., In this case not do some integers, people have been shot.
Initially, there were the so-called "common fractions". Their main disadvantage was that the unit fractions (denominators) could be any number. And in the process account it was necessary to bring the fractions to the same denominator. Then came the idea of creating a systematic fractions, in which the unit always has the same number of shares.
The first systematic fractions appeared in Babylon for 2 thousand years BC. In them the unit was divided into sixty shares, as "round" among the Babylonians was not considered to be 10 and 60. Babylonian fractions, unlike all sexagesimal system account, were borrowed by the ancient Greeks, and from them and the Europeans. This system was used in Western Europe, mainly astronomers, until the end of the XVI century.
In Ancient Rome there was dvenadtsatiletny system fractions (unit was divided into twelve parts). This was due to the fact that the monetary unit of the ancient Romans (unit weight) ACC was divided into twelve ounces. Ounce was called not only small coin, but in General the fraction, which we call "one-twelfth", even if it was used for length measurement.
Our ordinary fractions were widely used by the ancient Greeks and Indians. The rules of fractions contained Indian scientist Brahmagupta, in the IX century spread in Muslim countries by Muhammad Khorezm. In Western Europe they brought Italian merchant and scientist Leonardo Fibonacci of Pisa in the XIII century.
Finally, an outstanding Samarkand mathematician Giyaseddin the Jemshid al-Kashi (XIV-XV century) introduced decimal fractions, which we use now. When in the sixteenth century Dutch merchant and engineer Simon Stevin introduced them to Europe, they completely replaced the bulky sexagesimal fractions.