500 is a
children's game where a
gaggle of kids stands apart from another kid - who holds some sort of a ball. The individual kid throws the ball, and while it is
flying through the air, he/she shouts a number. The lucky kid who catches the ball also gains that number of points. The first kid in the gaggle to reach 500
points gets to be the kid to throw the ball to everyone else.
I've seen this played with a
tennis ball, a soccer ball, and (most often) an American
football.
The basic appeal of this game is that even the kids who can't
catch during a round have something to do - which is basically add up points and keep track of any
cheaters.