This is a wonderful game with many variations and lots of underlying mathematical ideas. It can be played cooperatively or competitively - or both, by working together in teams to compete with other teams. Children often master the rules more quickly than do adults, which adds to their fun. Here’s a brief outline of the way I introduce the game to people from about 8 years old to 80. If you would prefer a much more detailed approach, with many examples, go to page 30 of the Nov 2016 issue of The Variable .