Jāmiʿ al-ḥisāb: A Persian work attributed to Naṣīr al-Dīn Ṭūsī on Ḥisāb al-hawāʾ

The Persian monograph entitled Jāmiʿ al-ḥisāb (The Collection of Arithmetic) and attributed to Naṣīr al-Dīn Ṭūsī, is recorded in the catalogue of the Ayasofya (Hagia Sophia) Library under the title of al-Fārsiya fῑ al-ḥisāb. No mention is made of this work on Ḥisāb al-hawāʾ (a branch of practical arithmetic) and its attribution to Naṣīr al-Dīn Ṭūsī in any of the bibliographies and catalogues of old and new MSS. Ṭūsī has another book called Jawāmiʿ al-ḥisāb bi al-takht wa-al-turāb in which, by utilizing Indian numerals and an instrument named "takht" (board), he addresses Indian tradition in arithmetic. Although the two books attributed to Ṭūsī have similar titles, their contents differ squarely, following two distinct systems in their arithmetical approach. Jāmiʿ al- ḥisāb is mainly translated from Arabic, which according to the evidence provided in this paper, includes abridged Persian redaction from Ḡunῑyat al-ḥussāb by Humāmῑ Wāsiṭῑ as well as a number of topics presented in al-Takmila fῑ al-ḥisāb byʿAbd al-Qāhir al-Baḡdādῑ. The composition date of the treatise is unknown and its only manuscript accessible traces back to the late 8th-early 9th century-AH/circa 14th-15th century-AD.