We've tried to explain that he needs to keep it in a single, safe place.
Now it's lost. We don't know if he left it somewhere, or if it's buried in the dirt somewhere, or if it's behind some piece of furniture we haven't checked yet.
He had about $20 in it, plus about $25 in change (4 of which is a states coins collection he shares with Khai).
He has a $5 deposit on a $40 Pokemon game, and we're really hesitant to loan him the money. It'll take him a a couple of months to save up that much unless he really buckles down on his chores.
UPDATE yAY! OK, so, we owe him $20 for the last couple of weeks allowance, and he has $21 in undisputed change. Plus, we're trading in some games. All should be well, though he's still pretty upset over the loss. $20 at his age is a pretty big chunk of change.