非正數

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.

正 = 一 + 止 : Mnemonic symbol: a stick-figure with straight lines. James II of England (zh) really has to use the engine's bathroom ((e)ng4), but there's a stick-figure (正) blocking the stalls with a barrier (止). The stick-figure measures with a flute (一) whether James is tall enough to go. James stands very straight (正) to make himself as tall as possible.

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).