The Disturbing Abacus of Ibbi-adad Fourin is a 1663 years old piece made by Ibbi-adad Fourin, a merchant living in Istanbul / Constantinople / Byzantium.
Considering its age and the quality of the work, people consider it of some value.
It is engraved with central asian patterns and some symbols pertaining to Sufism.
Though exposed in this museum, this piece belongs to the last of the Fourin family, Chatur, currently living in Mumbai.