J1: why is the only way to subtract 7's by using up all the cake?
J0: they are really hungry because they are primes. They only have 2 proper factors.
J2: hmm, then what about 6? I guess 6 doesn't like cake?
J1: oh, the other numbers like cake, they just aren't as hungry if they have a lot of factors.
J2: what about 144? 144 must really not need to eat much extra!