12:59 AM
Just thought I'd say.

1:18 AM
One of my professor used to say that $\pi = 2$ was acceptable
And $\pi^2 = 10$

I had a professor who would use $\pi \approx 4$ in cases where there were already even coefficients floating around the problem.

1:42 AM
Really I don't even remember the last time I did actual calculations in physics
Like the last time I needed to compute numbers

1 hour later…
2:54 AM
typical...

2 hours later…
5:21 AM
For me, I tend to do things as symbolically as possible, thus I plug $\pi$ into my calculator (or computing software) and then it spits out the number (usually in terms of $\pi$)

If I need an approximation, then 3.14 is usually suffice for me

Wrong slash lol

I have memorise however the following in the past:
3.1415926535897932384626433832795028841971693993751058

However it seems I only technically memorise 3.141592653589793238462 because I tend to mismemorise 64 as 46
I memorise because it sounds like a (overly long) phone number

Seriously it is rare to have data good to more than five or so digits. I use 3.14159 when I want to feel swanky; Or more likely double pi = 4.0 * atan(1.0); the traditional incantation of the the guild of numericists (of which I am all but the lowliest novice).

5:38 AM
Indeed, that's why when I do calculations, I either use $\pi$ symbolically or just use 3.14

In fact, $2\pi$ is used so often that I already memorise 6.28 along with 3.14

I'm a greasy-handed wrenches and soldering irons physicist. Pi can stay a symbol only so long. Sooner or later you need measurements on the ground.