82
Kreiszahl rule
(lemmy.blahaj.zone)
(the title says "circle number", but there is no appropriate english translation that i could find)
The thing is, 2π is quite often for sure, but 1π isn't that rare and doubling is so much easier than halving that π still wins against τ
When it comes to pi, doubling is exactly as hard as halving.
Calculators usually have a pi button but not a tau button :shrug🤷♀️