Some teachers might give you a bad grade for wrong answers. In China, they might spank you in front of the rest of your classmates. Totally normal. Totally.
Say what you will about how weird this is and how it shouldn’t happen but that kid definitely took it in stride. Probably not his first spanking. I wouldn’t be surprised if he were giving the wrong answers just to get a taste of that sweet sweet sting on his buttocks. When an Asian guy is regularly getting math questions wrong, you know something’s off.