Much traditional scholarship holds that the period after about 1250 saw a decline in the production of scientific and philosophical works in the Arab world. This view is challenged by the impressive number of manuscripts written after that date in different Arabic-speaking countries that contain original treatises and commentaries. The work preserved in this manuscript, Nuzhat al-Hussāb al-Muhtasara min al-Muršida (The abridged amusement of the calculator from The guide), is a shorter version of Muršida fī Sina’at al-Gubar (The guide to the art of the numerals), an extensive treatise on arithmetical operations written by Aḥmad ibn Muḥammad ibn al-Ha’im (1356–1412) around the end of the 14th century. After completing his studies in Cairo, Ibn al-Hāʼim left for Jerusalem, where he worked as a teacher of mathematics until his death. Several of his works, and especially the Nuzhat al-Hussāb, have a clear educational aim. The introductory section, in which the author describes the Hindi numerals and their correspondences with the traditional Arabic alphabetical numeration (abjad), is followed by a lengthy exposition on the four arithmetical operations: addition (jam‘), subtraction (tarh), multiplication (darb), and division (qisma). Ibn al-Ha’im's activity as a professor did not prevent him from devising particularly witty solutions for mathematical problems: he is credited with the discovery of a method for solving general second-degree equations without using divisions of fractions.