a very emphatic answer(lemmy.blahaj.zone)

Take for example: 2/2*2 It is 0.5 or 2 depending on order. But if I were anything after high school (I was more complacent in high school, I guess) if someone gave me an arbitrarily solved equation or expression like this, I would be livid and raise hell at them for trying to do that.

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10_0@lemmy.ml

1 point

5 months ago

The fundamentals are literally the same, and the difference is in the words people use for the same thing, brackets and parentheses are used in the same way and only changes how the acronym is spelled. Powers, indices and exponents are the same thing. Here’s my version, PITDAT (parentheses, indices, times, divide, add, takeaway.)

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Ender of Games@sh.itjust.works

0 points

5 months ago

Yes, the fundamentals the same, higher orders come first. BUT…

-Multiplication comes before division in some forms, like PEMDAS. In the example I use, this changes the answer.

-When you apply an operation, you should specify what it is operating on. In all of these acronyms, addition comes before subtraction, but with a different example:

2 - 2 + 2

The minus sign only applies to the middle term, by convention. It is the equivalent of “adding negative two”. You can quickly see that this expression is equal to 2.

But if you use one of these acronyms, you end with this expression evaluating to -2. I would say it is almost universally accepted that 2 is the correct answer, and -2 is incorrect. Basically, all these acronyms end up being useless waste of time.

I don’t know if I conveyed this the first time, but, as a lover of pure mathematics, this is something that does not have application in life or in study. It’s an utterly useless waste of time. There is never a case where someone give you numbers like this, where it is not clear what order the numbers should be applied in.

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💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱@programming.dev

1 point

5 months ago

Multiplication comes before division in some forms, like PEMDAS. In the example I use, this changes the answer

If you have both multiplication and division then you do them left to right. PEMDAS doesn’t mean multiplication first, nor does BEDMAS mean division first. It’s PE(MD)(AS) and BE(DM)(AS) where the bracketed parts are done left to right.

you should specify what it is operating on

Left associativity means it always operates on the following term. i.e. terms are associated with the sign on their left.

The minus sign only applies to the middle term, by convention

By the rule of left associativity.

But if you use one of these acronyms, you end with this expression evaluating to -2

No it doesn’t. How on Earth did you manage to get -2?

all these acronyms end up being useless waste of time

No they’re not, but I don’t know yet where you’re going wrong with them without seeing your working out.

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Ender of Games@sh.itjust.works

0 points

5 months ago

If you have both multiplication and division then you do them left to right. PEMDAS doesn’t mean multiplication first, nor does BEDMAS mean division first. It’s PE(MD)(AS) and BE(DM)(AS) where the bracketed parts are done left to right.

You are adding more rules to protect a convention that doesn’t work and doesn’t mention them to begin with. If all that matters is higher orders first, then why bother having an acronym? Just say “Brackets, then higher orders”. Bam. Solved it with less words than any of the acronyms.

Left associativity means it always operates on the following term. i.e. terms are associated with the sign on their left.

As someone who studied mathematics, computer science, and engineering in university, I certainly don’t you to tell me how to do bare bones arithmetic. I know operators apply to the numbers to their right. Everyone does. You jumped right on by the point.

With 2/2*2, you don’t know if it is 2*2/2, or 2/(2*2). When you are dividing by numbers, you put them all in the denominator. If I had to put it in a line, I would at least do 2/(2)*2, to show what is in the denominator. If it is ambiguous, you have done it incorrectly.

By the rule of left associativity.

BY CONVENTION, as I said. You don’t have to repeat what I said a second time.

No it doesn’t. How on Earth did you manage to get -2?

wow. geez. I wonder.

If you can’t follow the steps guided for such a simple example, maybe we just shouldn’t have this conversation. It’s not like you could have tried in your head different orders to combine 3 numbers.

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💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱@programming.dev

0 points

5 months ago

Even your “BODMAS” isn’t universal, lots of people learn “PEMDAS” or “BEDMAS”

The rules are universal, only the mnemonics used to remember the rules are different

except for facebook and twitter

… and high school Maths textbooks, and order of operations worksheet generators, and…

2/2*2 It is 0.5 or 2 depending on order.

It’s always 2. #MathsIsNeverAmbiguous

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Ender of Games@sh.itjust.works

0 points

5 months ago

The rules are universal, only the mnemonics used to remember the rules are different

The rules and the acronyms describe different things. If you have to make more rules to say M and D are the same, and that you go left to right when you do them, then the basic rules you followed were flawed. The universal conventions of mathematics don’t need these acronyms confusing people.

high school Maths textbooks

I haven’t seen anything since early elementary school, not middle school, and certainly not high school. Regardless, if a textbook has it, it doesn’t make it right at all. If the acronyms are useless to learn, having them in a textbook doesn’t validate them.

and order of operations worksheet generators

…that’s one of the two examples you used? Did you think about that before you typed it out?

It’s always 2. #MathsIsNeverAmbiguous

IT IS AMBIGUOUS IN THIS POST AND ALL EXAMPLES I HAVE SHOWN. That is the problem at hand.

There is no real problem solving in trying to decipher poorly written shit. It’s the equivalent if English classes took time out to give students worksheets with “foder” written on them, and expecting students to find out if the writer meant “folder” or “fodder”- no sentence context, just following a list of “rules”. It is not difficult to write mathematical expressions with clear context to how numbers relate, even with the lazy shortcuts and shorthand that mathematicians love.

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💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱@programming.dev

0 points

5 months ago