You're dancing around gesticulating. They're dancing around gesticulating. Children are clapping and someone might even be singing, shaking an abacus in time to the music. Except that you're not teaching them a "foreign friend" dance, you're trying to get the correct change so you'll have the bus fare home. This podcast in Mandarin Chinese will help you stave off that three hour walk home, although you'll have to learn the art of the abacus on your own.