Addiator Arithma
ADDO Mod 16
ADDO-X 331
Brunsviga 13RK
Brunsviga 13ZK
Calculator "Superautomat SASL"
Facit 1004
Facit EK
Mechanical calculator MADAS
Mellita, Model V/16
Monroe Model L200-X
Nisa PK 5
Original Produx Calculator
Remington Rand Adding Machine
Walther DE 100
Walther RM
XxX calculator

Mercedes, 1905
At the beginning of the 20th century, many computational principles were protected by patents, and so computer technology manufacturers tried to develop their own computing methods as far as possible. The Mercedes plant, under the designer Christel Hamann, succeeded in doing this with the proportional lever method, which was used exclusively by Mercedes. This procedure enabled the construction of compact, fast desktop calculators with numerical results display and the calculation types addition, subtraction, multiplication and division. While the operation of multiplication and division was quite cumbersome with the older computer models (semi-automatic machines), the last models (fully automatic machines) achieved a simple operation with automatic result generation. The Euclid series was the manufacturer's workhorse and sold very well until the transition to electronic computing technology.