5 % 2 = 1
Freaking hell even ddg search gives that answer.
If I hear "% is a mathematical operator" one more time...
Submitted 2 weeks ago by asow8@mander.xyz to science_memes@mander.xyz
Comments
bryndos@fedia.io 2 weeks ago
moosetwin@lemmy.dbzer0.com 2 weeks ago
[deleted]jeff@programming.dev 2 weeks ago
You are misunderstanding what the remainder is.
5 % 2 == 1, because 5 == 2 x 2 + 1
10 % 7 == 3, because 10 == 1 x 7 + 3
Your “edit 2” is mostly correct. I don’t think of it “undoing” the division. But if that makes sense to you then I guess it’s fine
chaos@beehaw.org 2 weeks ago
It’s not undoing the division, it never happens in the first place. Remainders aren’t ever fractions, that’s the whole point, they’re left over because they can’t be divided evenly. 5 % 2, you can take 2 away twice and you’ll have 1 left over which can’t have 2 taken away.
Rivalarrival@lemmy.today 2 weeks ago
Modulo is much easier to understand with clocks.
Suppose It is currently midnight. What time will it be in 3 hours? 3 mod 24 = 3. It will be 03:00
What time will it be in 27 hours? 27 mod 24 = 3. It will be 03:00 we go through a whole day (24 hours) to get back to midnight, then another 3 hours.
What time will it be 48 hours from now? 48 mod 24 = 0. 48 hours from midnight will be midnight.
What time will it be 6 hours from now? 6 mod 24 = 6.
Conceptually, X mod Y means that instead of 24 hours per day, we are splitting the day into Y “hours”, labeled 0 to Y-1. We start at 0, and pass through X “hours”. X mod Y is the “hour” we finish up in at the end. 5 mod 2 means we have a 2-hour day, with hours 0 and 1. We pass through 5 of those hours. When we finish, are we at hour 0 or hour 1?
ornery_chemist@mander.xyz 2 weeks ago
don’t forget to make the space non-breaking :D
asow8@mander.xyz 2 weeks ago
Thank you for your comment! I had no idea what this meant, but I just looked it up. I will now be sure to use a non-breaking space from now on and look out for a number and its unit on different lines.
azi@mander.xyz 2 weeks ago
Let the operator m be such that x m = (1 metre)x
anton@lemmy.blahaj.zone 2 weeks ago
And since it’s a function with one argument we can interpret the exponent to mean repeated application.
xm³=x(1 meter)(1 meter)(1 meter)
xm³=x(1 meter)³
It all checks out.
protogen420@lemmy.blahaj.zone 2 weeks ago
what is the difference between an operator ane a function? is there any? one could argue that the common operators are just common useful functions and thus there is no reason why % is not one of them
asow8@mander.xyz 2 weeks ago
Yes, it was only after the comments mentioned modulo operator that I realized the % symbol has many meanings across different disciplines. I was coming from a chemistry perspective, and I should have specified from the beginning.
Kolanaki@pawb.social 2 weeks ago
I mean, it’s not like the percent operator only appears when the calculator is in scientific mode. 🤷♂️
OhNoMoreLemmy@lemmy.ml 2 weeks ago
I’m not being funny but it can be both.
Square root is an operator that maps a number to the positive number that when squared returns the original number, but there is also a square root symbol.
Similarly, % can be an operator that maps a number x to x/100, but there’s also a percent symbol.
It just depends if you’re talking about functions or fonts.
JayleneSlide@lemmy.world 2 weeks ago
Let’s not forget that it’s also the symbol for modulo operation. So many opportunities for ambiguity!
DozensOfDonner@mander.xyz 2 weeks ago
I thought they meant modulo actually
asow8@mander.xyz 2 weeks ago
The difference between you and the people this meme is about is you understand that both space or no space are fine.
For more context, I was trained to use a space between a number and its unit (e.g. 2 mol, 3 g, 1 M) for scientific writing. This includes the % sign when it follows a number (i.e. 100 %). So percent yields would be reported as 78 % instead of 78%. On the flip side, units that contain the % sign would not use a space. For example, mol% and wt% would not use a space to separate the % sign from the rest of the unit (i.e. 2 mol%).
Since I was taught this from the very beginning of university, I never really questioned where the convention came from. Now, I work for a PI who does not use the space for %. Every time I write something (presentations, manuscripts, etc.), they clarify that % is a mathematical operator so there is no space. After a search to defend my position, I found the SI brochure from the Bureau International des Poids et Mesures that clearly states the use of a space.
Recently in group meeting, while talking about something kind of related to units, they said that I believe there should be a space for %. I quickly clarified (and showed the SI brochure as evidence) that I do not “believe” there should be a space; this isn’t something I have created in my mind. Finally, they said that since it is their lab any manuscripts must follow their convention. Now when I write, I write my way and change it when I self edit before sending it to my PI.
flyos@jlai.lu 2 weeks ago
The “it’s my lab, so you follow my conventions” for a thing a silly as the space before % (and after you’ve used a rightful source to stand your point) is a very dumb power move IMO.
wiase@discuss.online 2 weeks ago
I was taught the same thing at uni (chemistry) but almost all journals in my field of work (toxicology) use no space.
Quibblekrust@thelemmy.club 2 weeks ago
Nah, dog. You’re arbitrarily ignoring negatives. The square root of 4 is ±2.
definitemaybe@lemmy.ca 2 weeks ago
I assume you’re nerd baiting* with that, but it’s infuriating how many math teachers actually teach that.
It’s not that complicated. x² = n isn’t the same thing as x = √2 because then square rooting isn’t a function, which is asinine. (Similarly to why 0! is defined to be 0, because otherwise it’s a stupid notation that would need a piecewise function definition for just about every single application of the factorial function.)
*link to xkcd: Duty Calls