ZOLOTOORDYNSKOE OBOZRENIE-GOLDEN HORDE REVIEW, ss.88-102, 2015
The Turkish author Ihsan Fazlioglu presents to attention of readers the third part of the article "A Masterpiece of Computational Mathematics" ("et-Tuhfe fi ilmi'l-hisab"). The author of this article presents the first example of an established scientific activity in the Golden Horde, which began before Janibek khan, during the reign of Uzbek khan. The work written in the Golden Horde on a mathematical topic occupies a special place because of the information contained therein. This treatise shows that the scientific activity in the Golden Horde, which began with the conversion to Islam, brought results in a short time and laid the foundations for "breakthroug" during the reign of Janibek khan. The author examines this composition from a historical perspective. The Computational book "et-Tuhfe fi ilmi'l-hisab", whose author is unknown, was handed during the reign of Uzbek Khan (1313-1342) to the ruler of the Crimean ulus of the Golden Horde Ebul-Muzaffer Giyaseddin Tuluktemir bey. After mentioning the distinguishing features of the work, the author pays particular attention to the definition of numbers, which is attributed to Muhammad b. Musa alKhwarizmi and which, at the moment, is not recorded elsewhere. The author analyzes the formula of approximate values of square and cube roots of irrational