Holiday Math: Should You Trade Your Gift?

Discussion Ideas
  • So, should you stick with your original choice or switch your choice?
    • Switch! You have a 66% chance of getting the good gift.
      • There are two goats, three choices—you have a 66% chance of originally choosing a goat.
      • So, it’s most likely that you’ve chosen a goat when Santa (or Monty Hall, or Wayne Brady, see below) reveals a goat behind a different door.
      • Since it’ shots likely you’ve chosen one goat and the other one is revealed, make the switch! You have a 66% chance of getting the good gift.


  • Why is it called the Monty Hall Problem? Was Monty Hall a famous mathematician?


  • Try the Monty Hall Problem with your class or family this holiday season.
    • Hide two give-away gifts and one swanky one in similar boxes.
    • Have a student or family member choose a gift.
    • Before revealing the gift they chose, reveal one of the (unchosen) give-away gifts.
    • Give the person the opportunity to change their answer.
    • Reveal the gifts!
    • What are the statistics for choosing a good gift when you switch your original choice? Do your statistics change the more often you play?



Vox: The Monty Hall Problem video

Nat Geo: World Statistics Day

One thought on “Holiday Math: Should You Trade Your Gift?

Leave a Reply