Comment on I dunno

• MotoAsh@piefed.social ⁨1⁩ ⁨day⁩ ago

  Hopefully you can see where their confusion might come from, though. PEMDAS is more P-E-MD-AS. If you have a bunch of unparenthesized addition and subtraction, left to right is correct. A lot of like, firstgrader math problems are just basic problems that are usually left to right (but should have some extras to highlight PEMDAS somewhere I’d hope).

  So they’re mostly telling you they only remember as much math as a small child that flunked.

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  • SpaceCadet@feddit.nl ⁨1⁩ ⁨day⁩ ago

    If you have a bunch of unparenthesized addition and subtraction, left to right is correct

    If you have a bunch of unparenthesized addition and subtraction, left to right doesn’t matter.

    1 + 2 - 3 = 1 - 3 + 2 = -3 + 2 + 1

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    • MotoAsh@piefed.social ⁨1⁩ ⁨day⁩ ago

      True, but as with many things, something has to be the rule for processing it. For many teachers as I’ve heard, order of appearance is ‘the rule’ when commutative properties apply. … at least until algebra demands simplification, but that’s a different topic.

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      • SpaceCadet@feddit.nl ⁨1⁩ ⁨day⁩ ago

        something has to be the rule for processing it

        Well the rule is: any order goes. Summation is commutative.

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    • kuberoot@discuss.tchncs.de ⁨20⁩ ⁨hours⁩ ago

      If you have a bunch of unparenthesized addition and subtraction, left to right doesn’t matter.

      Right, because 1-2-3=3-2-1.

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      • howrar@lemmy.ca ⁨9⁩ ⁨hours⁩ ago

        You flipped the sign on the 3 and 1.

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  • Feathercrown@lemmy.world ⁨1⁩ ⁨day⁩ ago

    PE(MD)(AS)

    Now just remember to account for those parentheses first…

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  • orbitz@lemmy.ca ⁨1⁩ ⁨day⁩ ago

    Huh I just remembered the orders of arithmetic but parentheses trump all so do them first (I use them in even the calculator app). Mean I assume that’s that that says but never learned that acronym is all. Now figuring out categories of words;really does my noodle in sometimes. Cause some words can be either depending on context. Math when it’s written out has (mostly) the same answer. I say mostly because somewhere in the back of my brain there are some scenarios where something more complicated than straight arithmetic can come out oddly but written as such should come out the same.

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• SkyeStarfall@lemmy.blahaj.zone ⁨1⁩ ⁨day⁩ ago

  I mean, arithmetic order is just convention, not a mathematical truth. But that convention works in the way we know, yes, because that’s what’s… well… convention

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  • marcos@lemmy.world ⁨1⁩ ⁨day⁩ ago

    Social conventions are real, well defined things. Some mathematicians like to pretend they aren’t, while using a truckload of them; that’s a hypocritical opinion.

    That’s not to say you can’t change them. But all of basic arithmetic is a social convention, you can redefine the numbers and operations any time you want too.

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