Karen, that's one of the things I hate too.
Why can't they tell you, "Just a moment, I've got the change." - Some do, some don't. It's easy, because all you have to do is count up as much as they gave you.

One thing that really peeves me is when they hand you a handful of change and don't tell you what it is. Then you have to sit there and count all of their pennies.