At the supermarket checkout
Cashier: Good morning. A total of 43.60 RMB. Do you need a plastic bag?
Lele: No, thank you. I've a shopping bag. Please wait a moment. I'm looking for it.
L: Sorry, I forgot to bring one. How much is one plastic bag?
C: The large one 6 mao, medium 4 mao, small 2 mao.
L: Give me a medium one.
C: Ok. A total of 46 RMB. You gave me 50 RMB. Here's your change of 4 RMB. It's a small banknote. Please accept.