
How does this poor man's log10 calculator trick work? - vdfs
https://www.reddit.com/r/explainlikeimfive/comments/fyh9qr/eli5_how_does_the_poor_mans_log₁₀_calculator/
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lonelappde
log (x) is approximated by √x iterated n times x^(0.5^n), multiplied by a
constant equal to (2^n + [fudge factor for √'s finite precision])

The best answer is a link to
[https://m.imgur.com/s9eBx5Z](https://m.imgur.com/s9eBx5Z) which solves the
problem in math notation.

There's another comment that describes that in words, and a bunch of reddit
chitchat.

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SamReidHughes
The best explanation was Vietoris’s:
[https://www.reddit.com/r/explainlikeimfive/comments/fyh9qr/e...](https://www.reddit.com/r/explainlikeimfive/comments/fyh9qr/eli5_how_does_the_poor_mans_log₁₀_calculator/fn207gm/)

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jackhalford
The same trick (approximating with a first order Taylor series), is also the
basis of quake's famous fast inverse square root [1]. I love these methods
because they always involve a "magic constant".

[1]
[https://en.m.wikipedia.org/wiki/Fast_inverse_square_root](https://en.m.wikipedia.org/wiki/Fast_inverse_square_root)

