This is a fun activity that I like to use as a reward for classes. Students get "money" to spend at the auction based on their grade in the class. Items are then placed on the auction block and the bidding begins! There are numerous things on the list from food to homework passes; the goal is to put things on their that students will want-also, there needs to be a limit (not everyone that goes to an auction can actually get what they want). For those students that may not know how an auction works, I like to do an example before actually starting the auction. After the auction is over, you can either continue on with class or let students have the rest of the period as part of their reward.