自然數

自 = 丶 + 目 : Mnemonic symbol: a hand mirror, which someone uses to look at themselves.

The Eye of Providence (目) is looking at itself (自) in a handheld mirror (自) in the space station's bathroom (Ø4). It think it's indeed looking very good, since Zorro (z) attached a petal (丶) to its eye (目).

然 = 灬 + 肰 : Robinson Crusoe is grilling some dog meat on his BBQ in the anthill's kitchen, but it's hard to do it correctly because of all the animal rights activists. They think it's not right to grill dog meat.

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).