Chopsticks

the egg is the hard one.

thirty seconds at a ramen counter: hold to grip, drag to the spoon, and do not squeeze the egg

A thing held between chopsticks stays put only inside a band of grip: too little and it slides out, too much and soft foods shoot out sideways, as egg does to everyone. That band differs by food; egg is the narrowest.

Concepts: friction, physics.

An interactive you play with one thumb, on Wundr.