this post was submitted on 27 Nov 2023
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Those same people do math incorrectly and shout at everyone else to do it their way.
2+2=5
Don't take my word for it research about it yourself there are lots of good videos on YouTube the government and science liars don't want you to know the truth /s
You got me there
For extrem values of 2.
For those confused
2.25+2.25=4.5 rounds to 2+2=5
2.5+2.5=5 truncates to 2+2=5
Both can crop up in programming, depending on the situation.
2.25 + 2.25 = 4.5
If you add two floats together then the output is a float, if you add an int and a float together the output is a float. Computers will always perform the calculation as is, unless you explicitly tell them to perform a rounding operation.
However, if you stuff them into an int at the last minute, you can get that effect.
Under the hood, it's floats. On the output, it's ints.
It's obvious and silly with small examples. The problem can creep in when you are using larger libraries or frameworks.
A few months back I had a floating point that had a single 1 like 16 digits past the decimal place and I couldn't get rid of it.
Remember when Terrance Howard tried to explain how 1x1=2 because bird people from Atlantis tricked us? Good times.
There are four lights
Just look at those viral math problems. I recently saw one that was something like (1+2*3)*(1*0) and most comments were arguing if it was 7 or 9
I think you mean (1+2*3)*(1*0).
Escape your asterisks, kids.
I mean, it doesn't matter.
I was going to claim 9 because I though there was some markdown that italicised things with a single ^, and your intent was (1+2³). Before the (1•0) of course.
It does if you forgot everything you learned in school
(1+2*3)*(1*0) = (1+23)(1*0)
And I agree. You're completely missing my point, though
The only advice I can give is to re-read the thread, starting from @[email protected]'s comment. If the source of your confusion is that you don't know what escaping the asterisks means, then just ask
Of course, there's also the times where we just make the research hard to do.
Like, we teach kids PEMDAS, but then don't actually follow PEMDAS in the original textbooks that introduce it and definitely not in common math or physics texts.
Like, you'll see 1/2√r in Feynman's lectures being written not to represent ½√r = √r / 2 as pemdas would suggest, but 1/(2√r).
Similarly, the original textbooks that introduced PEMDAS, if you read them, actually followed what you might call PEJMDAS, where multiplication via juxtaposition is treated as binding tighter than explicit multiplication, so 1÷2(2+3) would be interpreted not as ½(5) but as 1 ÷ (2 * 5), but they considered that so obvious they didn't bother to explicitly spell it out in the rules.
And now we have Facebook memes and tiktok livestreams arguing about what 1÷2(2+3) actually means.
Also by the time you've learned order of operations, you've outgrown the ÷ operator. You would never write 1 ÷ (2 * 5), you would write it with a proper numerator and denominator like anyone outside of elementary school would.
I hate these math problems you see on social media. No one would write that way or code that way. It is ambiguous, and even if it weren't it is still hard to figure out. I think in my entire career I have seen one single line of code that took PEMDAS to sort out, I remember that line and the programmer told me that they were exploiting a feature of the complier to get slightly faster results. He was an annoying person
Laughs in RPN
In the UK it's (or at least was) BODMAS. Just to complicate things further.