He studied the algebra of Maghrebi mathematician
Ibn al-Bannā and published
The Epistle of the Number, a translation and detailed commentary on Ibn al-Bannā's 13th century treatise
Talḵīṣ ʿAmal al-Ḥisāb ("A summary of the operations of calculation"). The work is notable in being the first known Hebrew-language treatise to include extensive algebraic theories and operations. His astronomical works include
Oraḥ selulah (Upraised Path), a set of tables in Hebrew for conjunctions and oppositions of the Sun and the Moon,
Keli Ḥemdah (Precious Instrument), which describes a unique
equatorium of his own invention, functioning on the
Ptolemaic theory of epicycles,''
and Keli Memutsa (Intermediate Instrument)
, which describes another unique instrument of his own design, a combination astrolabe-quadrant. He is the author of a commentary on the
Passover Haggadah, titled
Pesach Doros (
Passover of later generations) and printed by Mekhon Bet Aharon ṿe-Yiśraʼel in 2000.
Leshon ha-Zahav (Golden Language), an explication of the names for units and measurements found in the
Hebrew Bible. He is probably the author of a commentary on
Maimonides'
Laws of the Sanctification of the Month, found in the same MS as
Leshon ha-Zahav with no author given. He also wrote songs, published as
Shirei Rabbeinu Itzḥak ben Shlomo ibn al-Aḥdab (1987). He is known to have composed a work called
Shir ha-Shirim, but it has not survived. ==References==