Keywords: Solo calculator - Ridai Museum of Modern Science, Tokyo - DSC07525.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 02 14 own Daderot other versions cc-zero Portable mechanical calculators in the Ridai Museum of Modern Science |