In years to come?

What will archeologists make of this.
2-3, at least, decades ago a young friend of mine was having problems with his maths. He asked me about multiplying fractions, so I tried to teach him.
I have a malformed nail which more nearly resembles a "claw" - Mam used to call it my "Chicken Paw". One day you'll see why, now I've mentioned it.
Anyway, I used that nail to draw an example on the wall.
You, maybe can't see it but I showed him how to:-
1/2 X 3/4 = 3/8; I can still see most of it.