非负数

非 = 三 + 丿 + 丨 : Mnemonic symbol: a negative film (photography).

Frankenstein's monster (f) made an effort to photograph the Eiffel Tower (ei1), but now his negative (非) is a big mess. In front of the tower he set up a camera on a Cartesian coordinate system (三) as a tripod, and he attached a banana (丿) and a dinosaur bone (丨) to the camera so that he can finely tune the angles. All was for naught as he now holds the messed up negative in his hands.

负 = ⺈ + 贝 : Mnemonic symbol: an opossum (负鼠) who carries her babies on her back.

A few pals practice their cosplay on the space station's bathroom. They want to reenact the town musicians of Bremen, and so Frieda Fuchs stands at the bottom, the crab is on top of Frieda, the crane is on top of the crab, the opossum is on top of the crane, and the opossum carries her babies on her back.

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).