History of Hindu Mathematics: A Source Book v1.c7.s17.t3: Abû Sahl Ibn Tamim (950)

v1.c7.s17.t3.1

Ibn Tamim, a native of Kairwân, a village in Tunis in the north of Africa, wrote in his commentary on the *Sefer Yesîrâh*: "The Indians have invented the nine signs for marking the units. I have spoken sufficiently of them in a book that I have composed on the Hindu calculation, known under the name of *Hisâb al-ghobâr*."