What makes it an appropriate challenge for middle school students is this:
• It encourages students to begin with a guess
• Then it encourages them to act out the problem
• The evidence that emerges will improve their mathematical intuition
• Then they are encouraged to answer the question "Why?"
If you have a middle school student, you can help by playing the game with them (you can do it with three playing cards, representing the three doors). Keep track of your results. What do you observe? How do you explain this result?
