This variation on Twenty Questions teaches kids a bit of information theory and lets them take a different approach to powers of 2.
First, the kids should be familiar with the regular game of Twenty Questions.
Then, ask as an open-ended question: "Suppose instead of the whole world. you were only allowed to think of certain objects. How many questions would it take to find the right one? What if the questions had to have only yes/no answers?"
Down to Grade/Age:
Up thru Grade/Age: