Post by Pat Ballew

1321 Ibn al‐Bannāʾ al‐Marrākushī (29 December 1256 – 31 July 1321), was a Maghrebi Muslim polymath who was active as a mathematician, astronomer, Islamic scholar, Sufi and astrologer. 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 continued fractions. *Wik