For years, we’ve accumulated change in a big-ass jar on our dresser. About once a year, we take it down to the grocery store and use the automated machine to turn it into useful money. As part of that process, I’ve often wondered to what degree one could use the weight of the change to estimate the value; it shouldn’t be as crazy as it sounds, since it’s easy to know the average weight of each type of coin, and presumably someone knows the average distribution of coins in circulation. I just never got around to figuring it out.

Now, via BoingBoing, I’ve found that someone did, though this implementation doesn’t use a known distribution of coins; instead, it asks the user to grab a random handful and enter that as the ratio to use. I still think the ratio in circulation has to be knowable, but I’ve yet to find it anywhere. The Heathen jar is getting pretty full, though, so maybe it’s time to finish my method and create estimates using it and CoinCalc before taking the jar down to Kroger.