四
=
儿
+
囗
:
Mnemonic symbol: a four-leaved clover. Socrates (s) is working out in the bathroom of the space station (Ø4). He's lifting four (四) wooden boxes (囗), and wonders why they are so heavy. He doesn't know that inside one of the four boxes, the monkey king (儿) is hiding and secretly laughing at him - until the monkey king comes out and surprises Socrates with a four-leaved clover (四).
月
=
⺆
+
二
:
Yu the Great (yu) is modelling a moon (月) in the elevator's bathroom (e4). He uses a stapler (⺆) to staple a lot of capacitors (二) together to form a moon shape, while the real moon is sitting for him.