Following Euclid, notes about recipes, etc. were the closest thing to how we think at algorithms today. Also, there was also the inventions of mathematical methods. For example, Sieve of Eratosthenes, Euclid’s algorithms, and methods for factorization square roots.
It seems common to us now to list things out in the order we will do them in. But, in Mathematics at that time — it was not a common idea. (16h 23min, jan 1, 300 y BC – 11h 1min, jan 1, 800 y)