The Odhner Pin-wheel calculator as, invented by Willgodt T. Odhner in St. Peterburg Russia, in 1874. It could be used for addition, subtraction, multiplication, and division. Especially division required multiple rotations of the crank forwards and backwards. See: http://www.vintagecalculators.com/html/odhner.html(approve sites)
skills/usinganodhnertypepin-wheelcalculator.txt · Last modified: 2009/01/13 11:33 (external edit)
