A failed inspection is just an invitation to use a different method until it passes.

There's less and less reason to do it (and it's never 5). On systems without floating point you might want to round it a bit, but only if the specific thing you're doing allows it, and even then you're more likely to do a fixed-point approach by using e.g. 314 and dividing by 100 later, or adjusting that value a bit so you can divide by 128 via bitshift if you're on a chip where division is expensive. However, in 2025 you almost certainly should have picked a chip with an FPU if you're doing trigonometry.

And while rounding pi to 3 or 4 is certainly just a meme, there are other approximations which are used, like small-angle approximations, where things like sin(x) can be simplified to just x for a sufficiently small x.

For back-of-the-envelope or mental calculations, pi is often 3 or 10^(1/2).

The latter is better than 1% accurate, and has nice properties when doing order-of-magnitude/log space calculations in base 10.

There's a lot of weird stereotypes out there that make no sense. Like the whole "programmers wear thigh high socks" thing. Where did that even come from?

you've never seen anybody simplify it to 3 when doing head calcs without a phone nearby?

it doesn't happen often, in fact I've seen it once. in a decade.