Later on our teaching trip to Peru, Cathy and I visited the Museo Larco. There in one of the showcases were quipus!
Quipus were the main system employed by the ancient Inca culture to record information and events. The knotted cords were used to record countable information.
The colors, knots and distances between the knots enabled those who used the quipus to identify the type of object or the characteristics of the population being recorded.
photos in film grain