>This algorithm allows people to multiply two numbers if all they can do is multiply and divide by 2, and add.
Yes, and the algorithm of making N groups of M and then counting allows people to multiply if all they can do is count. And they will do it far faster than the shaman every time.
>And yet is it so efficient it is how computers multiply.
> Yes, and the algorithm of making N groups of M and then counting allows people to multiply if all they can do is count. And they will do it far faster than the shaman every time.
I don't know. I notice that I am confused, so I know that between my existing beliefs and the details of this story, something important is fictional.
My strongest guess is that it's the stones. In any base > 1 the algorithm is efficient. In unary (counting stones), it inefficient to the point of being nonsensical.
So my guess is that this was not used by counting stones, but with some form of positional number system, and that in the retelling, stones have been added as a way to make it sound more "tribal".
Edit: Alternatively, it may be the idea that they're doing this exactly. If the doubling side is done by rough estimation (eyeballing the size of the piles), it might be faster.
This algorithm allows people to multiply two numbers if all they can do is multiply and divide by 2, and add.
> It couldn't have been efficient since it is patently idiotic.
And yet is it so efficient it is how computers multiply.