• tamal3@lemmy.world
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    1 year ago

    It’s organized so that more powerful operations get precedence, which seems natural.

    Set aside intentionally confusing expressions. The basic idea of the Order of Operations holds water even without ever formally learning the rules.

    If an addition result comes first and gets exponentiated, the changes from the addition are exaggerated. It makes addition more powerful than it should be. The big stuff should happen first, then the more granular operations. Of course, there are specific cases where we need to reorder, or add clarity, which is why human decisions about groupings are at the top.

    • The big stuff should happen first, then the more granular operations

      The “big stuff” is stuff that is defined in terms of something else. i.e. exponents are shorthand for repeated multiplication… and multiplication is shorthand for repeated addition, hence they have to be done in that order or you get wrong answers.

      • AdrianTheFrog@lemmy.world
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        8 months ago

        “Wrong answers” only according to our current order of operations, math still works if you, for example, make additions come first (as long as you’re consistent about it).

        OFC it is a convention and to change it you would have to change all expressions ever written all at the same time, to avoid confusion between competing standards. I’m not arguing that it should be changed, only that there is no ‘high truth’ behind it.

        • “Wrong answers” only according to our current order of operations

          No, according to arithmetic.

          math still works if you, for example, make additions come first

          No, it doesn’t - order of operations proof. The only way it could work with addition first is if we swapped the definitions of addition and multiplication around… but then we still have the same order of operations, all we’ve done is swapped around what we call addition and multiplication!

          there is no ‘high truth’ behind it.

          There is when it comes to order of operations.

          • AdrianTheFrog@lemmy.world
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            8 months ago

            Let’s assume for a minute addition comes first. We know 2+3 is 5, and 5x4 is the same as 5+5+5+5=20. What is the issue with that?

              • AdrianTheFrog@lemmy.world
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                8 months ago

                If we change how equations are parsed so addition comes before multiplication, 2+3x4 is not the equation required to solve that problem. 2+(3x4) is the equation needed. You can’t change how equations work and then expect all equations to work the same after the change.

                If your argument is that this will add parentheses where we didn’t need them before, that’s valid and its the reason we do it this way in the first place. But that doesn’t mean there is anything fundamentally wrong with having a different system of writing equations in which operations are executed in a different order.

                Our whole system of writing equations is just a convention, and yes, it is a good and easy to understand and use way of writing math. But there is no fundamental truth behind it, only that it is simpler for the majority of use cases.

                • Noted that you didn’t answer my question - the answer is I have 14 litres of milk. 2+3+3+3+3=14 litres. When you did “arbitrary addition first”, you got 20, which is wrong, which is why no other order of operations rules work than the ones we have.

                  You can’t change how equations work and then expect all equations to work the same after the change

                  In actual fact the point is that they will except for what ever your new notation is. e.g. if we instead defined + to mean multiply, and x to mean add, then we would do + before x, and again, that would be the only order of operations which works. i.e. the only order which gives us 14 litres.

                  that doesn’t mean there is anything fundamentally wrong with having a different system of writing equations in which operations are executed in a different order

                  No, and if you did that, you would again arrive at only one order of operations rules which works, cos I still have 14 litres, and the Maths in this new system still has to give an answer of 14 litres, not 20.

                  Our whole system of writing equations is just a convention

                  Nope, it’s all rules, found in any Maths textbook, and if you don’t obey the rules you get wrong answers (like you did when you got 20).

                  But there is no fundamental truth behind it

                  Yes there is - I have 14 litres, and only 1 set of order of operations rules gives that answer.

                  only that it is simpler for the majority of use cases

                  If you follow the rules of Maths then it is correct for every use case. That’s why they exist in the first place.

                  • AdrianTheFrog@lemmy.world
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                    8 months ago

                    I think you misunderstand my argument. I could use still math to solve a real-world problem with an altered order of operations. You could still do anything you can do with regular math, if you had a different order of operations. You could make a programming language that parses your inputted expressions with a different order of operations and still use it to calculate collisions or render a 3d scene or do anything else that involves math. Do you need me to calculate something, to prove it to you?

                    The order of operations is just part of a system of notation and any system of notation that exists in the world is inherently arbitrary. The same way the way that how we draw the number 3 or the number 5 has no inherent meaning behind it other than the convention of how we interpret it, the order of operations is nothing more than a standard part of the notation. Again, I’m not saying that we should or could change it, as there would be no way to indicate which convention we are using and the standard order of operations works perfectly fine.