In [*The Sand Reckoner*](https://en.wikipedia.org/wiki/The_Sand_Reckoner), Archimedes comes extremely close to discovering (inventing?) both the positional number system and some form of scientific notation: he uses the geometric sequence of powers of $10$ to express very large numbers and formulates and proves the fact that $10^m \times 10^n = 10^{m+n}$ (except that since he counts from $1$, it's a bit more messy).