In fact, this kind of mathematical game is a sort of disbelieving sport for me — maybe the opposite of schadenfreude (kind of like the Buddhist concept of mudita, come to think of it). (inc.com)
It's a very mathematical game, and the cards are functionally equivalent to unique 4 - digit base three numbers. (alephblog.com)
Its contents are a miscellany of mathematical games, puzzles, stories and factoids. (newscientist.com)