For some definitions of "fun"

How many calories in a slice of pizza? I think this is a fun party game: tell your friends to think, but not say aloud, how many calories there are in an average, not ginormous, normal slice of cheese pizza, no special toppings. Insist that they think of an actual number before anyone says anything, because the fun part is the ridiculously wide variation in the numbers they’ll come up with. The first time I tried this, the lowest guess was less than a fifth of the highest.