Great day to teach your kids, grandkids, nieces or nephews about pi. Challenge them to measure things and see how close they can get to the constant. My challenge to one particular little girl ended up in a flurry of 6 measurements with a tape measure, the closest of which was 3.1416. Not bad!
For more on Pi and Pi Day, as well as Pi to one million digits, see here.
And, Scientific American is offering yearlong digital subscriptions today for, appropriately, $3.14.