Considering the evolution of ancient accounting systems, the author discovers its similarity with the evolution of numeracy in children. Based on this typological similarity, based on the ideas of L.S. Vygotsky, as well as on the work of the American researcher D. Schmandt-Besser on counting systems in the oldest Middle East, the author reconstructs the processes in the evolution of consciousness that led to the appearance of abstract counting, writing and, as a result, conceptual thinking.