# Ibn al-Banna' al-Marrakushi

Ibn al‐Bannāʾ al‐Marrākushī (Arabic: ابن البناء المراكشي), full name: Abu'l-Abbas Ahmad ibn Muhammad ibn Uthman al-Azdi al-Marrakushi (Arabic: أبو العباس أحمد بن محمد بن عثمان الأزدي) (29 December 1256 – 31 July 1321), was an Arab Muslim polymath who was active as a mathematician, astronomer, Islamic scholar, Sufi and astrologer.

## Biography

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 and al azdi means he was from the big arab tribe Azd. 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.

## Works

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 (Arabic: تلخيص أعمال الحساب) (Summary of arithmetical operations), includes topics such as fractions and sums of squares and cubes. Another, called Tanbīh al-Albāb, 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.