My Personal History of Abacus: From Physical to Mental

I’d like to talk about abacus—an ancient cognitive artifact that is still widely used in China. I began learning abacus to do arithmetic since I was six and interestingly, as time went on, there emerged a virtual abacus in my mind every time I need to calculate, which directly manifests the ideal-material-duality of artifacts mentioned by John Dewey, Marx, and Hegel.[……]