Keywords: Monroe calculator - Ridai Museum of Modern Science, Tokyo - DSC07573.JPG en Exhibit in the Ridai Museum of Modern Science Tokyo University of Science Kagurazaka campus - 1-3 Kagurazaka Shinjuku-ku Tokyo 2015-02-20 02 09 12 own Daderot other versions cc-zero Mechanical calculators in the Ridai Museum of Modern Science Monroe calculators |