Oh Chatty, what would we do without you?
Okay, I'm with you on the change thing, but here's another part that drives me nuts.
After the cashier has plugged in the amount of money you are giving them, try adding a penny, or some amount of change to make your change more even. They don't know what to do. They don't know how to figure out change for themselves without the machine telling them how much to give.
Something I bought came to some dollar amount and 51 cents. After she punched in the amount I was giving her I added a penny so she would only have to give me the two quarters.
She told me I COULDN'T DO THAT! I proceeded to tell her how much change to give me and totally confused her. She wouldn't take my penny. It was too confusing. Oh boy....