In this audio presentation conducted in the late 1990s at a homeschool convention, Sam Blumenfeld gives a lecture on the history of arithmetic: https://www.podomatic.com/podcasts/shurtleffhal/episodes/2020-12-17T07_25_48-08_00
This audio originated from the Sam Blumenfeld Archives: https://campconstitution.net/sam-blumenfeld-archive/