Numerical digit
From India, the thriving trade between Islamic sultans and Africa carried the concept to Cairo. Arabic mathematicians extended the system to include decimal fractions, and Muḥammad ibn Mūsā al-Ḵwārizmī wrote an important work about it in the 9th  century. The modern Arabic numerals were introduced to Europe with the translation of this work in the 12th century in Spain and Leonardo of Pisa's "Liber Abaci" of 1201. In Europe, the complete Indian system with the zero was derived from the Arabs in the 12th century.
Arabic parts
Beginning in the tenth century, many Arabic manuscripts were translated into Latin, becoming the means by which Classical astrology found its way back to Europe. Medieval astrologers, most notably the major 13th-century Italian, Guido Bonatti, a contemporary of Dante, assumed it was the Arabs who originated the concept of the lots, and hence they came eventually to be called the "Arabic parts".