Introduction This paper charts some of the converging lines of thought, research and argumentation that point to a theory of situated learning as a possible next step in understanding the learning and teaching of mathematics. The story might begin almost anywhere in Western history. I have arbitrarily picked the date 1478. In that year, when the Treviso Arithmetic was printed (Swetz, 1987), the relation of math learning and everyday experience may have been less of a conundrum than it is today. There existed no contradiction between specialized mathematical education and universal socialization for everyday living, as there is today. At that time there were only a few master computers. They accepted future merchants as short-term apprentices. In this socially organized math practice the apprentices learned from the master computers the math they needed to carry out typical business transactions.