The first of the Arabic writers mentioned is Al-Kind[=i] (800-870 A.D.), who wrote five books on arithmetic and four books on the use of the Indian method of reckoning. Sened ibn `Al[=i], the Jew, who was converted to Islam under the caliph Al-M[=a]m[=u]n, is also given as the author of a work on the Hindu method of reckoning. Nevertheless, there is a possibility[36] that some of the works ascribed to Sened ibn `Al[=i] are really works of Al-Khow[=a]razm[=i], whose name immediately precedes his. However, it is to be noted in this connection that Casiri[37] also mentions the same writer as the author of a most celebrated work on arithmetic. To Al-[S.][=u]f[=i], who died in 986 A.D., is also credited a large work on the same subject, and similar treatises by other writers are mentioned. We are therefore forced to the conclusion that the Arabs from the early ninth century on fully recognized the Hindu origin of the new numerals. Leonard of Pisa, of whom we shall speak at length in the chapter on the Introduction of the Numerals into Europe, wrote his _Liber Abbaci_[38] in 1202. In this work he refers frequently to the nine Indian figures,[39] thus showing again the general consensus of opinion in the Middle Ages that the numerals were of Hindu origin. Some interest also attaches to the oldest documents on arithmetic in our own language. One of the earliest {11} treatises on algorism is a commentary[40] on a set of verses called the _Carmen de Algorismo_, written by Alexander de Villa Dei (Alexandra de Ville-Dieu), a Minorite monk of about 1240 A.D. The text of the first few lines is as follows: "Hec algorism' ars p'sens dicit' in qua Talib; indor[um] fruim bis quinq; figuris.[41] "This boke is called the boke of algorim or augrym after lewder use. And this boke tretys of the Craft of Nombryng, the quych crafte is called also Algorym. Ther was a kyng of Inde the quich heyth Algor & he made this craft.... Algorisms, in the quych we use teen figurys of Inde." * * * * * {12} CHAPTER II EARLY HINDU FORMS WITH NO PLACE VALUE