因變數

因 = 囗 + 大 : Mnemonic symbol: the close reasoner René Descartes.

因 = 囗 + 大 : In front of the encampment ((e)n1), René Descartes (因), Maud Younger (y) and a robot (大) are starting a big rave. The robot sits inside a big box (囗) and is the master of ceremony, while René and Maud are dancing on the square. They started this rave to collect money for a good cause (因).

变 = 亦 + 又 : In anthill's bathroom the also-ran is sparring with Brunhilde. In her mind she imagines changing into a boxing grizzly bear.

变 = 亦 + 又 : I think 变 does look like a grizzly bear with a beret. 又 is the snout, and the two eyes are the two strokes of 八.

数 = 娄 + 攵 : Sheldon Shrimp (shu) occupied a lunar mansion (娄) inside of the space station (Ø3) although he knows that it is to be torn down. Outside of his lunar mansion the construction (or rather destruction) workers are already counting (数) down from ten. When they count (数) zero, they will start taking down the whole thing with their sledgehammers (攵).