nostr:npub1aum4qlaqrl9jlqahrt57czar9ah84nelfv0w75n28nk0d7x22z8q565jx0 

Vintage NYC DOE c. 1960 pencil with carefully replaced fresh eraser sharpened with a plane to a razor point. 

It's imbued with the spirit of long gone math classes and basically solves problems by itself*.

*not true really... maybe... unless.