http://web.media.mit.edu/~stefanm/society/som_final.html Numerical Mechanisms and Children's Concept of Numbers Numerical Mechanisms and Children's Concept of Numbers Numerical Mechanisms and Children's Concept of Numbers Numerical Mechanisms and Children's Concept of Numbers one-to-one and the stable-order principles http://web.media.mit.edu/~stefanm/society/som_final.html commonsense reasoning