Sure, until you actually need the correct result of the circumference of a circle and think pi is 5.
Comment on PI is what
F4lcon@discuss.tchncs.de 1 year ago
It’s to make the numbers simple because they aren’t important, the methodology is
LemmysMum@lemmy.world 1 year ago
aesopjah@lemm.ee 1 year ago
Like, at least make it 3 instead of 5. Still allows for mental math
LemmysMum@lemmy.world 1 year ago
It’s fucking pi. It’s a constant that will never change in their entire lives, just teach reality the first time instead of making up a thousand little lies to correct later.
fsxylo@sh.itjust.works 1 year ago
thousand little lies
What do you mean there are more than 3 states of matter?
aesopjah@lemm.ee 1 year ago
Gotta cut it off at some point though, right? How many decimals? 10, 4, 1, or 0?
Plus, this is a test not the knowledge delivery. Some thing as ‘assume a flat plane with no friction’ for a physics test. Yeah it’s not 100% accurate but the test taker can be evaluated on the methods
hansl@lemmy.world 1 year ago
Or just use a cube and say one side is 5 long. Does it really have to be a cylinder?
Reddit_Is_Trash@reddthat.com 1 year ago
This is what we get when we cater to the dumbest kids in the class.
echodot@feddit.uk 1 year ago
The dumbest kids in class can’t handle algebra.
It’s a really bad question for all sorts of reasons. Firstly because they defining π as 5 (it’s not even close to the real value) and they never explain what h is.
Also you should probably just use letters everywhere at this point and not use π unless π equals π.
LemmysMum@lemmy.world 1 year ago
No child left behind = every child left behind.
zeppo@lemmy.world 1 year ago
I was thinking more it’s Freedom Pi from Florida or Texas or something.
vivadanang@lemm.ee 1 year ago
Pretty sure they call that frito-pi in Texas
F4lcon@discuss.tchncs.de 1 year ago
So? You think you’ll get the correct result by using 3? Or 3.14? Not quite. You can only get infinitesimally close to the correct result by increasing digits of pi.
And of course, if you really need that circumference for something critical, guess what? You use the things people developed for this very problem, software packages, and so on. And of course, you get it double checked, triple checked.
If it’s assume pi is 5, it’s not misinformation. If they point guns at kids and say it’s 5 for real, then yes.
LemmysMum@lemmy.world 1 year ago
Or you could just use 3.14 which is infinitesimally more correct than 5, not lie about the number and aim for correctness and accuracy so people learn how to do things right the first time.
If you can’t handle a few decimal points then you aren’t ready for pi, go back to third grade.
F4lcon@discuss.tchncs.de 1 year ago
I don’t think you understand what infinitesimally means! It means the opposite- you want to use ‘infinitely’ there.
Now, not being a condescending asshole, I really take issue with you calling an approximation a ‘lie’. And honestly, who’s multiplying decimal points mentally? That’s difficult. Use a calculator. Want to avoid calculators for an exam? Simplify! That’s why they use 5 and not 3.14.
UnknownQuantity@lemm.ee 1 year ago
Then let’s teach kids to use Wolfram Alpha.
F4lcon@discuss.tchncs.de 1 year ago
Of course. They already use it like it’s some kind of hack. Make it official. Teach them the ins and outs of Wolfram. Better than memorising and regurgitating information, no?
TheOakTree@lemm.ee 1 year ago
I get that, it’s like rounding gravitational acceleration (on earth) to 10…
But why don’t they just use 3, preceded by a “pi is a little more than 3, but for now we’ll round down to 3.”
jadero@mander.xyz 1 year ago
Especially given that using π=3 is accurate enough for most daily use by ordinary people for ordinary things.
F4lcon@discuss.tchncs.de 1 year ago
3 or 5 is equally inaccurate. Engineers usually round it up from however accurate they need it. Scientists usually try to use it to as many digits of significance as they can.
3 or 5 is equally inaccurate, it doesn’t matter which you use if you think that’s accurate. Most people, engineers and scientists and mathematicians, use computers, but you’ll find they can get inaccurate pretty quickly too.
Again, 3 or 5 is a meaningless distinction to round an irrational number to. 3 is not an accurate value of pi in any sense and neither even is 3.14.
jadero@mander.xyz 1 year ago
I would draw your attention to the difference between mathematics and reality. Although mathematics is extremely useful in modeling reality, it’s important to remember that while all models are wrong, some are nonetheless useful.
Thus, a household gardener or storage tank owner or a builder of small boats can choose the appropriate diameter of hose, tank, or pontoon very effectively by rounding PI to 3 but cannot do so when “rounding” to 1 or 5. In these cases, it literally doesn’t matter how many decimal points you use, because the difference between 3 and any arbitrary decimal expansion of PI will be too small to have concrete meaning in actual use.
Under the philosophy you are promoting, it would be impossible to act in the physical world whenever it throws an irrational number at us.
I don’t know, but I suspect that there is a whole branch of mathematics, engineering, or philosophy that describes what kinds of simplifications and rounding are acceptable when choosing to act in the physical world.
The real world in which we act has a fuzziness about it. I think it’s better to embrace it and find ways to work with that than to argue problems that literally have no numerical solution, at least when those arguments would have the effect of making it impossible to act.
Yawnder@lemmy.zip 1 year ago
Such an ordinary people thing to say.
jadero@mander.xyz 1 year ago
Just an ordinary person doing ordinary things :)
merc@sh.itjust.works 1 year ago
The only thing I can think of is that they wanted the math to be easy, and somehow thought 3 was easier than 5. But, that’s hard to believe because the only other numbers used were all 10s, so it’s 3101010 vs. 5101010.