Let π = 5

Gork@lemm.ee to Lemmy Shitpost@lemmy.world – 806 points –
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To be Devil's Advocate:
Given that the rest written in Comic Sans, it may be an early elementary school exercise, aimed at teaching kids to do multiplications. In this case, it's tolerable and/or defensible to find a simplification for pi.

That said, making pi equal to 3 would have been more accurate for that...

Unless the kid is even slightly above average and finds the idea that pi equaling 5 confusing.

...if they're above average, I think they'll figure out the explicitly defined variable. I think the instructor is trying to make sure this problem doesn't require a calculator and figured defining pi as 5 makes it clear that you can treat it as a whole number. 3 would be more accurate and just as easy, but meh idk that this is that great of a blunder.

You can be a smart kid and not realize that adults are lying.

I remember the Peas and the Punnett Square. Sure, mendelian genetics explains pea plant colors, but doesn't explain dog fur colors. Just providing a footnote that more completed genetics exists would have been nice.

Heh nice try but we don't write textbooks or exams for the outliers.

Or it's from an ME. They seldom can remember the rounded value of Pi, but they're pretty sure it's somewhere between 3 and 4. But you probably should use 5 just to be safe.............

That's a dumb way of teaching and you are a dumb devils advocate for saying it. Go to H E double hockey sticks.

Even in engineering it is common to just round pi to 3 and quickly estimate whatever it is your doing.

In astronomy, pi=1 or 10, depending on whether you’re trying to over or under estimate something. Because when you’re trying to estimate distances measured in millions of light years, the difference between 3 and 10 is just one or two orders of magnitude on a small number. It’s pretty common for astronomers to do napkin math by rounding every single number to the nearest zero. 91k becomes 100k for instance. Because the napkin math estimations are just trying to gauge whether some celestial event or object is a thousand light years away, ten thousand, a hundred thousand, etc… And pi becomes 10, because that’s the nearest round number.

Fermi Estimation. Where you're dealing with something so big, you're just interested in the magnitude.

Excuse me what? I've been an engineer for a decade and have never met anyone that would do that. We have calculators.

I think they mean napkin math. Like you're in a meeting and they ask for a general idea if something will work or not

I suppose. I'm still internally outraged and haven't run into such a situation before, but I accept this.

To be fair most of the situations where I've run into this have never involved pi, and sometimes it's just qualitative.

That makes sense. I feel like if you're at the point where pi is meaningfully involved, you should probably do your math.

Yeah I agree. It isn't that hard to set up things in Excel to get a decent answer.

We all have phones with calculators, don't really need to do napkin math anymore

Depends on the level of precision you need. If I want the volume in a 500 foot long, 3 inch pipe to roughly estimate how much supply I need to order, I wouldn't need a calculator. It would very roughly be 90-95 ft3. (Divide 500 by 4 two times and multiple by 3)

Then I would spend 5 minutes double checking myself haha.

I feel like a proper engineer would call only going two places past the decimal "rounding pie".

I need a new maitre'd for a restaurant I am opening. How busy are you?

Not very, but I'll require lots of pay.

How does 1 million a minute sound?

Ill take it!

I'll give you the hardest 30 minutes I've worked in my life, and then retire.

So you do know how to act like a decent human. Damn. Well the restaurant closed. I guess you can just be nice for your own esteem now.

Nope. I had sold my house to move and told the kids already. Now I'm jaded I just lost out on 30 mill and we're homeless. I'll be an ass forever, now.

Well you were before. So the fam should be used to it.