Ibn al-Banna' al-Marrakushi

• Name — Ibn al‐Bannāʾ al‐Marrākushī • Born — 29 or 30 December 1256 • Birthplace — Marrakesh, Almohad Caliphate • Died — 31 July 1321 • Place of death — Marrakesh, Marinid Sultanate • Era — Islamic Golden Age • Main Interests — Mathematics, astronomy • Influences — Al-Zarqali, Ibn Ishaq al-Tunisi

Ahmad ibn Muhammad ibn Uthman was born in the Qa'at Ibn Nahid Quarter of Marrakesh on 29 or 30 December 1256. His nisba al-Marrakushi is in relation to his birth and death in his hometown Marrakesh. His father was a mason thus the kunya Ibn al-Banna' (lit. the son of the mason). Ibn al-Banna' studied a variety of subjects under at least 17 masters: Quran under the Qari's Muhammad ibn al-bashir and shaykh al-Ahdab. ʻilm al-ḥadīth under qadi al-Jama'a (chief judge) of Fez َAbu al-Hajjaj Yusuf ibn Ahmad ibn Hakam al-Tujibi, Abu Yusuf Ya'qub ibn Abd al-Rahman al-Jazuli and Abu abd allah ibn. Fiqh and Usul al-Fiqh under Abu Imran Musa ibn Abi Ali az-Zanati al-Marrakushi and Abu al-Hasan Muhammad ibn Abd al-Rahman al-Maghili who taugh him al-Juwayni's Kitab al-Irsahd. He also studied Arabic grammar under Abu Ishaq Ibrahim ibn Abd as-Salam as-Sanhaji and Muhammad ibn Ali ibn Yahya as-sharif al-marrakushi who also taugh him Euclid’s Elements. ʿArūḍ and ʿilm al-farāʾiḍ under Abu Bakr Muhammad ibn Idris ibn Malik al-Quda'i al-Qallusi. Arithmetic under Muhammad ibn Ali, known as Ibn Ḥajala. Ibn al-Banna' also studied astronomy under Abu 'Abdallah Muhammad ibn Makhluf as-Sijilmassi. He also studied medecine under al-Mirrīkh. He is known to have attached himself to the founder of the Hazmiriyya zawiya and sufi saint of Aghmat, Abu Zayd Abd al-Rahman al-Hazmiri, who guided his arithmetic skills toward divinational predictions. Ibn al-Banna' taught classes in Marrakesh and some of his students were: Abd al-Aziz ibn Ali al-Hawari al-Misrati (d.1344), Abd al-Rahman ibn Sulayman al-Laja'i (d. 1369) and Muhammad ibn Ali ibn Ibrahim al-Abli (d. 1356). He died at Marrakesh on 31 July 1321.

Ibn al-Banna' wrote over 100 works encompassing such varied topics as Astronomy, Astrology, the division of inheritances, Linguistics, Logic, Mathematics, Meteorology, Rhetoric, Tafsir, Usūl al-Dīn and Usul al-Fiqh. One of his works, called Talkhīṣ ʿamal al-ḥisāb (Summary of arithmetical operations), includes topics such as fractions and sums of squares and cubes. Another, called Tanbīh al-Albāb,[3] covers topics related to: • calculations regarding the drop in irrigation canal levels, • arithmetical explanation of the Muslim laws of inheritance • determination of the hour of the Asr prayer, • explanation of frauds linked to instruments of measurement, • enumeration of delayed prayers which have to be said in a precise order, and • calculation of legal tax in the case of a delayed payment He also wrote an introduction to Euclid's Elements. He also wrote Rafʿ al-Ḥijāb 'an Wujuh A'mal al-Hisab (Lifting the Veil from Faces of the Workings of Calculations) which covered topics such as computing square roots of a number and the theory of simple continued fractions.

Ibn al-Banna' al-Marrakushi is recorded with the occupation arithmetician. Recorded as mathematician, astronomer, astrologer, writer and arithmetician. Recorded at birth as ابن البناء المراكشي, أحمد بن محمد بن عثمان.