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.
Tunisian Arabic
Classical Arabic began to be installed as a governmental and administrative language in Tunisia that was called then "Ifriqiya" from its older name "Africa" during the Muslim conquest of the Maghreb in 673. The people of several urban cities were progressively influenced by Arabic. By the 11th century, through contact of local languages such as African Romance or Berber with Classical Arabic, some urban dialects appeared in the main coastal cities of Tunisia. The dialects were slightly and characteristically influenced by several common Berber structures and vocabulary like negation because Tamazight was the language of contact for citizens of that period. The new dialects were also significantly influenced by other historical languages.