I'm trying to come up with some math problems (word or otherwise) that get to the meaning of adding zero, but I'm getting stuck because it seems just too simple to me.
I have come up with questions like "John is having a birthday party and he invites five friends over but nobody shows up. How many people are at the party?". While this question gets to the problem at hand, it might be too simple to understand the meaning of adding zero. This problem also suffers from the possibility that first graders will answer like so, "Well there would be three people at the party because John's mom and dad would be there too."
Any ideas?