The Kitab al-bayan wa al-tadhkar (Book of demonstration and memorization) is a manual on calculation. It is listed under the author's name in Katib Celebi, Kashf al-zunun, Beirut, 2008, vol.1, p.317 (2428). It was translated into Hebrew by Musa Ibn Taybun (Moses bin Tibbon) in 1271 AD. His father, Samuel bin Tibbon was a translator of Maimonides into Hebrew. The present manuscript was originally bound with another treatise copied on the same paper with a colophon dated AH 905/1499-1500 AD (owner's correspondence). It is very likely that the present copy is also early 16th century.