structural:expansion, stylistic:style_transfer
Measures, calendrics and mathematics

Physical measures used by the Inca were based on human body parts. Units included fingers, the distance from thumb to forefinger, palms, cubits and wingspans. The most basic distance unit was thatkiy or thatki, or one pace. The next largest unit was reported by Cobo to be the topo or tupu, measuring 6,000 thatkiy s, or about 7.7 km (4.8 mi); careful study has shown that a range of 4.0 to 6.3 km (2.5 to 3.9 mi) is likely. Next was the wamani, composed of 30 topo s (roughly 232 km or 144 mi). To measure area, 25 by 50 wingspans were used, reckoned in topo s (roughly 3,280 km or 1,270 sq mi). It seems likely that distance was often interpreted as one day's walk; the distance between tambo way-stations varies widely in terms of distance, but far less in terms of time to walk that distance.