In reply to a post by TinyMongomery:

Euler’s identity, surely the most beautiful of equations.

Yes; that you can take unity, two transcendental numbers and an imaginary number and combine them so simply to sum to zero I still find mind-boggling... it shows there has to be some order underlying the universe somewhere

Remember using a hand punch to produce these cards. Had to memorise the Hollerith codes and had to write what the characters were (or supposed to be) across the top.

Edited by gomezz (Fri 20-Jun-25 11:12:15)

There is also a similar method for hand-calculating cube roots but I never got the hang of that.

I think I remember the maths teacher telling us that the method could, in principle, be extended to any (integer) root, but above the square root it rapidly got out of hand.

(And we'd probably never use it anyway- if you really did need a reasonably accurate higher root, expose yourself to the joys of seven figure log tables )