Keep The Change, However Much It Is

(One afternoon a customer walks in and orders a $3 item. He pays with a $5 bill and the coins needed to get a flat amount back. Before I can give him his change, he pulls three $1s out of his pocket.)

Customer: “I just realized I had these extra dollars on me. Think I could give you these then you could give me a $5 back?”

Me: “Not a problem.” *completes the transaction* “You know, this kind of looks like you spent $3, only to be given $5 and a drink.”

Customer: “What? How? Explain this to me.”

Me: “Ignoring the coins, your order was $3. You gave me $5, for $2 change. Then you handed me $3 so I combined them—”

Customer: “And I got my $5 back.”

Me: “And you got your $5 back.”

Customer: *laughs* “Okay. Tell me that one more time.”

(We ended up repeating this conversation three more times, the customer laughing harder each repeat. In the end, he thought it was amusing enough to let me keep the change!)