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Comment on I dunno

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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    MotoAsh@piefed.social ⁨1⁩ ⁨day⁩ ago
    No, you completely misunderstood my point. My point is not to describe all valid interpretations, but the one most slow kids will be taught.
    
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    Quatlicopatlix@feddit.org ⁨1⁩ ⁨day⁩ ago
    Yes thank you! If you have a sum it is really great to order it in a way that makes it better to ad in your head and i think that lots of people do that without thinking about it. X=2+3+1+6+2+4+7+5 X=2+3+5+4+6+7+1+2 X=5+5 + 10 +7+1+2 X=10 + 10 + 7+3 X=10 + 10 + 10
    
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- kuberoot@discuss.tchncs.de ⁨19⁩ ⁨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 ⁨8⁩ ⁨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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