• quail@lemmy.ca
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      8 days ago

      Order of operations only has one rule: Bedmas (or pemdas if you’re not from north america)

      • AxExRx@lemmy.world
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        8 days ago

        Huh it was always pemdas in both highschool and college in new England for me… they were also always parentheses. ‘Brackets’ only reffered to ‘[ ]’ which were reserved for matrices or number sets, eg 2*[2,5,8]+2= [6,12,18]

      • PeriodicallyPedantic@lemmy.ca
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        8 days ago

        If you look at the arguments on math forums, you’ll see that there isn’t just one rule.

        It is a convention, and different places teach different conventions.
        Namely, some places say that PEDMAS is a very strict order. Other places say that it is PE D|M A|S, where D and M are the same level and order is left-to-right, and same with addition vs subtraction.
        And others, even in this post, say it’s PEMDAS, which I have heard before.

        “Correct” and “incorrect” don’t apply to conventions, it’s simply a matter of if the people talking agree on the convention to use. And there are clearly at least three that highly educated people use and can’t agree on.

        • different places teach different conventions

          But they all teach the same rules

          some places say that PEDMAS is a very strict order

          Which is totally fine and works

          Other places say that it is PE D|M A|S,

          Which is also totally fine and works

          even in this post, say it’s PEMDAS

          Also totally fine and works

          it’s simply a matter of if the people talking agree on the convention to use

          No-one has to agree on any convention - they can use whatever they want and as long as they obey the rules it will work

          can’t agree on

          Educated people agree that which convention you use doesn’t matter.

          • PeriodicallyPedantic@lemmy.ca
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            9 hours ago

            That’s not true Here is an example:
            8÷2x4
            PEMDAS: 8÷2x4 = 8÷8 = 1
            PEDMAS: 8÷2x4 = 4x4 = 16
            PE M|D A|S: 8÷2x4 = 4x4 = 16
            And thats not even getting into juxtaposition operations, where fields like physics use conventions that differ from most other field.

            but you’re missing the point. It could be SAMDEP and math would still work, you’d just rearrange the equation. Just like with prefix or postfix notation. The rules don’t change, just the notation conventions change. But you need to agree on the notation conventions to reach the same answer.

            • That’s not true

              Yes it is

              PEDMAS: 8÷2x4 = 4x4 = 16

              Yep.

              PEMDAS: 8÷2x4 = 8÷8 = 1

              Nope. PEMDAS: 8x4÷2 = 32÷2 = 16. What you actually did is 8÷(2x4), in which you changed the sign in front of the 4 - 8÷(2x4)= 8÷2÷4 - hence your wrong answer

              PE M|D A|S: 8÷2x4 = 4x4 = 16

              Yep, same answer regardless of the order 🙄

              And thats not even getting into juxtaposition operations,

              Which I have no doubt you don’t understand how to do those either, given you don’t know how to even do Multiplication first in this example.

              where fields like physics use conventions that differ from most other field

              Nope! The obey all the rules of Maths. They would get wrong answers if they didn’t

              you’re missing the point

              No, you are…

              It could be SAMDEP and math would still work

              No it can’t because no it wouldn’t 😂

              you’d just rearrange the equation.

              Says someone who didn’t rearrange “PEMDAS: 8÷2x4 = 8÷8 = 1” and got the wrong answer 😂

              The rules don’t change

              Hence why “PEMDAS: 8÷2x4 = 8÷8 = 1” was wrong. You violated the rule of Left Associativity

              • PeriodicallyPedantic@lemmy.ca
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                6 hours ago

                Ok, then explain prefix and postfix, where these conventions don’t apply. How can these be rules of math when they didn’t universally apply?

                Says someone who didn’t rearrange "PEMDAS

                The order of operations tells us how to interpret an equation without rearranging it. When you pick a different convention, you need to rearrange it to get the same answer. What you did was rearrange the equation, which you can only do if you are already following a specific convention.

                No it can’t because no it wouldn’t 😂

                All conventions can produce the correct answer, when appropriately arranged for that convention, because the conventions are not laws of mathematics, they are conventions.

                Nope! The obey all the rules of Maths. They would get wrong answers if they didn’t

                They obey the laws of math. Conventions aren’t laws of math, they’re conventions. And a quick Google search will tell you that not everyone puts juxtaposition at a higher precedent than multiplication; it’s a convention. As long as people are using the same convention, they’ll agree on an answer and that answer is correct.

                You can be mean all you like, that doesn’t change the nature of conventions