The present article develops a framework for interpreting Upper Palaeolithic artefacts from an analysis of material complexity, numeration systems and timekeeping using cultural categorizations, insights on the emergence of number terms in language, and the astronomy practices of 33 contemporary hunter-gatherer societies. Our key findings suggest that astronomy originates in the ability to estimate and infer contextual relations among natural phenomena and transitions from these natural associations to material representations and cognitive technologies that mediate conceptual apprehensions of time as a substance that can be quantified. Given that artefacts may act as scaffolds for explicit concepts of numbers, and numbers scaffold explicit concepts of time, prehistoric artefacts such as the Blombos Cave beads (c. 75,000 bp), Abri Blanchard and Cellier artefacts (c. 28,000 bp), and plaque from Grotte du Taï (c. 14,000 bp) may represent similar scaffolding and conceptual development in numbers and time. It is proposed that the prehistoric societies making these artefacts possessed, in addition to material complexity, the abilities to express quantities in language and to use material externalization and cognitive technologies. Furthermore, the Abri Blanchard artefact is proposed to represent externalized working memory, a very modern interaction between mind and material culture.