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Whats your such opinion
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this post was submitted on 07 Dec 2023
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Asklemmy
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Let's see.
8÷2×(2+2) = 8÷2×4
At this point, you solve it left to right because division and multiplication are on the same level. BODMAS and PEMDAS were created by teachers to make it easier to remember, but ultimately, they are on the same level, meaning you solve it left-to-right, so....
8÷2×4 = 4×4 = 16.
So yes, it does equal 16.
Depends on whether you're a computer or a mathematician.
2(2+2) is equivalent to 2 x (2+2), but they are not equal. Using parenthesis implicitly groups the 2(2+2) as part of the paretheses function. A computer will convert 2(4) to 2 x 4 and evaluate the expression left to right, but this is not what it written. We learned in elementary school in the 90s that if you had a fancy calculator with parentheses, you could fool it because it didn't know about implicit association. Your calculator doesn't know the difference between 2 x (2+2) and 2(2+2), but mathematicians do.
Of course, modern mathematicians work primarily in computers, where the legacy calculator functions have become standard and distinctions like this have become trivial.
It seems you are partly correct. You are correct in saying that this is how it used to be done (but that was 100 years ago, it seems) and you are correct that in modern times, this would be interpreted as I did it, above.
Link: https://mindyourdecisions.com/blog/2019/07/31/what-is-8-%C3%B7-22-2-the-correct-answer-explained/
I'm old but I'm not that old.
The author of that article makes the mistake of youth, that because things are different now that the change was sudden and universal. They can find evidence that things were different 100 years ago, but 50 years ago there were zero computers in classrooms, and 30 years ago a graphing calculator was considered advanced technology for an elementary age student. We were taught the old math because that is what our teachers were taught.
Early calculators couldn't (or didn't) parse edge cases, so they would get this equation wrong. Somewhere along the way, it was decided that it would be easier to change how the equation was interpreted rather than reprogram every calculator on earth, which is a rational decision I think. But that doesn't make the old way wrong, anymore than it makes cursive writing the wrong way to shape letters.
No, it wasn't. The claim that the rules were changed is a debunked myth.
No, that video is wrong. Not only that, if you check the letter he referenced Lennes' Letter, you'll find it doesn't support his assertion that the rules changed at all! And that's because they didn't change. Moral of the story Always check the references.
Only if that's what the programmer has programmed it to do, which is unfortunately most programmers. The correct conversion is 2(4)=(2x4).
Actually it's only in the 90's that some calculators started getting it wrong - prior to that they all gave correct answers.
But that's not the same thing as 8÷2(2+2). 2x(2+2) is 2 Terms, 2(2+2) is 1 Term. 8÷2×(2+2)=16 ((2+2) is in the numerator), 8÷2(2+2)=1 (2(2+2) is in the denominator)
Under pemdas divisor operators must literally be completed after multiplication. They are not of equal priority unless you restructure the problem to be of multiplication form, which requires making assumptions about the intent of the expression.
Okay, let me put it in other words: Pemdas and bodmas are bullshit. They are made up to help you memorise the order of operations. Multiplication and division are on the same level, so you do them linearly aka left to right.
Pemdas and bodmas are not bullshit, they are a standard to disambiguate expression communication. They are order of operations. Multiplication and division are not on the same level, they are distinct operations which form the identity when combined with a multiplication.
Similarly, log(x) and e^x are not the same operation, but form identity when composited.
Formulations of division in algebra allow it to be at the same priority as multiplication by restructuring it as multiplication, but that requires formulating the expression a particular way. The ÷ operator however is strictly division. That's its purpose. It's not a fantastic operator for common usage because of this.
There are valid orders of operations, such as depmas which I just made up which would make the above expression extremely ambiguous. Completely mathematically valid, order of ops is an established convention, not mathematical fact.
This comment is the epitome of being confidently wrong on the internet.
For one misinterpretation? Are you sure about that?
There was 3 misinterpretations - see my reply to them.
I made a hashtag for people #LoudlyNotUnderstandingThings :-)
No, they're not.
Yes, they are.
In other words, they are the inverse operation of each other - welcome to why they have the same precedence.
It's a mathematical fact.
Not literally. It's only a mnemonic, not the actual rules.
Yes, they are. Binary operators have equal precedence, and unary operators have equal precedence.