Technically, the last one is pretty easy, as well, since 198 is fairly close to 200. 200*189 = 37800, then subtract 189 twice (or say it's close to 200 then add 11 twice) for 37,422.
... At least, that's the way I tend to do math like this.
You go first...easyOver 10 secondsFine by me!Wait, why are you running away!?1 secondThis...this is cheating!Out of time! Apparently Chinese shipgirls are not that tough after all! I won! HahahahahahahaChinese shipgirl, if you can answer 3 of my questions in a row, I'll admit defeat!Rules: answer every question within 10 seconds completely by mental arithmetic7 secondsIt's your turn now!