Hamann 300


This machine uses the same latched wheel construction which all Hamann calculators share as well as the same way an automatic division is performed.  

Apparently it origins from the Belgian army.  There is a carrying case available (not photographed).



Enter a number and hit the “+” or the “-” key.


Start on the utmost left.  Enter the first number and store it in the main register by hitting the “I” key.  Press  the “+” key until the counter has reached the desired least significant number.  Then move the carriage one position to the right.  Press  the “+” key until the counter has reached the desired next 2nd significant number etc..


Push the “:” button in the right  (it should stay pressed-down). Push the “-->” button.  The carriage moves to the right to the divide position shown by the red arrow.  Enter the first number and push the “+” key to store it in register III. Enter the second number and hit the “I” key to store it in register “I”.  Now push the “<--” key to start the division.  

Function of some keys, switches etc

Calculator InfoRepair information & pictures of internals
Hamann 300Hamann 300Hamann 300
Hamann 300Hamann 300

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Serial number:

Built in:


Rotation speed:


Production until:


102 266


Addition, Subtraction, Half automatic Multiplication and  Fully automatic Division

360 rot/min


1959 (Known serial numbers run from 102.001 - 105.000)

DM. 2465,- in 1956 (Source: 1956 price table)