Stepped-drum Multiplier – Machines a Calculer

The machine uses as transfer mechanism a stepped-drum system invented by LEIBNIZ.

Early mechanical calculator for basic arithmetic.

A variant of the mechanical arithmometer.

MADAS stands for: Multiply Automatically Add Subtract. This machine is best characterized by a significant improvement to division.

An acronym-named, specialized calculation tool.

Compact, hand-held mechanical calculator.

Advanced version of Curta Model 1.