Abstract
Taqī al-Dīn al-Rāṣid is one of the most important representatives of the Ottoman tradition on
mathematical sciences. His research focus being on astronomy, astronomical instruments, mathematics,
optics, mechanics, and physics is understood from his surviving works. Taqī al-Dīn’s establishment and
management of the Istanbul Observatory, which was the first observatory in the Ottoman Empire, made
him an important figure in many ways. However, despite the aforementioned importance, the mathematics
he learned, taught, produced and used has been a subject for very few studies. The primary way of
determining the quality and the level of a work is to look at the kind of tools used for its creation. Therefore,
this article will present the edition princeps, the translation and the evaluation of Taqī al-Dīn al-Rāṣid’s
treatise on algebra, al-Nisab al-mutashākila fī ʻilm al-jabr wa-l-muqābala. It will be presented in the context
of the idea that revealing a scientific character and the career of scholars who stand out in mathematical
sciences can be possible by analyzing their mathematical works. The nature of the science of algebra, which
can be applied to any problem encountered on any subject regardless of geometry or arithmetic, makes this
idea more meaningful. For the correct examination of classical mathematical works, first the original text
is verified and transformed into a format that provides an easy reading, then it is to be translated into the
desired language. Finally a mathematical analysis and historical evaluation are needed to explain the main
structure and justification of the content of the article.