That pillow brings up some interesting questions... Like, is the pillow invisible? Or floating? I'd assume the former, but then that means that his pillow just disappears and appears at random now. It's a cursed pillow.
She's just damn lucky they use a base 10 numeric system, otherwise, all her algebra would be wrong as hell (or maybe she's just good at math in other bases, but considering her knowledge of many other subjects is surface level, I doubt that)