I've hoped Dan Bouk would post something about these colorful paper wheels ever since he first told me about them. They are tools used by the pioneering statistician Alfred Lotka in the mid-30s to work through the probabilities governing a life; they're like odd, flat dice, with the sides all weighted differently. Does that even make sense? Read Dan! He explains them better! http://censusstories.us/2018/08/11/foudray.html