Almost every ancient culture had a system for counting. In this video we discuss the number systems of the ancient Babylonians, the Egyptians, the Indus valley culture, the Chinese, the Greeks and the Romans. In each case, a more primitive system (perhaps of strokes, twigs or pebbles) was refined by introducing larger units, or denominations, often from a base 5 or base 10 foundation. This is an excellent starting point for understanding our rather sophisticated system: the Hindu-Arabic number system.