Two children plus one favorite toy on equals trouble. No, this is not the beginning of new math word problem. But it is a scenario that leads to disruptions in families every day. Two children each want the same toy. In this case, this toy was a recent gift from Grandma. On this particular morning, Andrew is the first one to claim possession. Lydia knows this means that she will not be able to play with this toy for at least several hundred years. So Lydia, with tears welling up in her eyes, goes off to find Mom to inform her of this great injustice.