Comment by eru

> Multiplications of this word length, one should clarify. It's not that multiplication was an inherently more expensive or different operation back then (assuming from context here that the "old days" of coding inner loops in assembly language pre-date even the 32-bit ALU era). Binary multiplication has not changed in millennia. Ancient Egyptians were using the same binary integer multiplication logic 5 millennia ago as ALUs do today.

Well, we can actually multiply long binary numbers asymptotically faster than Ancient Egyptians.

See eg https://en.wikipedia.org/wiki/Karatsuba_algorithm