Fushi no Kami: Rebuilding Civilization Starts with a Village - Vol. 1 Ch. 2 - Clues To Deciphering

[MangaDex]

 

[welcome2atlantis]

Ooh... the ability to make mental calculations seems to be a powerful card there. Good blackmailing.

 

[rmremail]

The life expectancy is wrong: In a pastoral village like this, if you survived childhood (and many people didn't), then there was a good chance that you would live into your 60's (though a 60 year old back then would look like a 90 year old now)

 

[kinayas]

Using names is exactly how they cracked the rosetta stone