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See if you know the correct answer
- Thread starter Apple_Robert
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8/2*(2+2)For grins and math giggles, see if you can find the correct answer.
8 ÷ 2(2+2) =
1.
8
----- * (2+2)
2
2.
8
----- *4
2
3.
4 * 4
= 16
Now:
8/(2*(2+2))=1
I know this is a raging controversy, but it's clear to me that the expression is ambiguous, and therefore incorrectly written. That means there's no right or wrong answer any more than there's a right of wrong answer for 8 ÷ 2(2+ . Math notation is simply a convention for expressing computations clearly. If it's not clear then it's faulty.
It doesn't use sufficient grouping (parentheses). That's why different people, different teachers, and even different calculators produce different answers.
There is sufficient parentheses there. The only reason the one calculator got the wrong answer is a bug in the calculator. There reason people are getting 1 is because they forgot the order of operations.
Yeah, but if it's straight up Martinis shaken or stirred, I vote for 0. Those are just nasty. (Apologies in advance to anyone who can drink a straight Martini)
If this is honestly how you feel, you might as well be wrong. Your logic is the equivalent of guessing and getting it right but for all the wrong reasons.
Order of operations is
P
E
MD - this is critical because multiplication and division are both multiplication. They're not truly unique
AS - same here, addition is the same as subtraction (subtraction is adding a negative)
The equation is intentionally vague because you get 8÷2×4, which violates the model. You would never write and equation like that.
The unambiguous way to write this is either
No one with a math background would EVER use the division symbol.
Omigosh, now you bring martinis into this. You really do want this moved to PRSI, don't you?
If this is honestly how you feel, you might as well be wrong. Your logic is the equivalent of guessing and getting it right but for all the wrong reasons.
Order of operations is
P
E
MD - this is critical because multiplication and division are both multiplication. They're not truly unique
AS - same here, addition is the same as subtraction (subtraction is adding a negative)
The equation is intentionally vague because you get 8÷2×4, which violates the model. You would never write and equation like that.
The unambiguous way to write this is either
No one with a math background would EVER use the division symbol.
You can rewrite the equation anyway you want but the way it’s currently written is the answer is 16.
The way it’s written is elementary math and not ambiguous.
If you are writing code for a computer program you would have to change how it’s written.
And you're still incorrect.
Not much else to say. The equation is written incorrectly. The end.
I saw this on Twitter the other day before it made its way here.
It was clearly constructed to be a "blue dress/gold dress" or "Do you hear Yanny or Laurel" type scenario to have people passionately advocate for their particular view (just like it is here).
It was clearly constructed to be a "blue dress/gold dress" or "Do you hear Yanny or Laurel" type scenario to have people passionately advocate for their particular view (just like it is here).
Yup. According to Steven Strogatz, Jacob Gould Schurman Professor of Applied Mathematics at Cornell University
So, it's really unclear which answer is correct, so both answers are fine.
The only way to be wrong here is to rudely insist that one answer is right and the other is wrong. You have managed to be wrong.
[doublepost=1564962587][/doublepost]
Yeah, I chose a superior source (an Ivy League Applied Mathematics professor).
The creator of the video you posted, Presh Talwalkar, is a Stanford Economics major without any qualifying credentials. You two can be wrong together, but neither of you is alone.
[doublepost=1564962816][/doublepost]
The reality is the equation doesn't imply intent. Division isn't shown with the obelus in math, and despite what some here say, when you learn order of operations, you don't learn it like that. Division is always shown using fractions to clarify intent.
Talwalker seems to be unaware of the Style Guide for Physical Review Journals. It's one of the references cited when I quoted from Wikipedia regarding implicit multiplication.
Here's a link to the PDF:
https://cdn.journals.aps.org/files/styleguide-pr.pdf
On page 1, it shows the latest revision is from 2011. This is quite a bit more recent than 1917. While I can appreciate that an older notation and limited typography will be relevant to its time, the style guide for a prominent journal that was revised in 2011 is also relevant to its time.
On page 21, it states the order to follow for "slashed fractions":
(e) When slashing fractions, respect the following con-
ventions. In mathematical formulas this is the accepted
order of operations:
(1) raising to a power,
(2) multiplication,
(3) division,
(4) addition and subtraction.
ventions. In mathematical formulas this is the accepted
order of operations:
(1) raising to a power,
(2) multiplication,
(3) division,
(4) addition and subtraction.
Directly above item (e) is an example that incorporates both slashed fractions, i.e. with the "/" symbol, and what it calls "built-up" fractions, which are ones where a horizontal line demarcates numerator from denominator.
The ÷ symbol doesn't appear in the style guide, or at least it doesn't yield any results for a PDF search.
I guess the question now is whether ÷ and / are equivalent symbols, or whether they're different, or whether there's some possibility for ambiguity or context-dependence.
Meanwhile, I'm definitely going with the "units-dependent argument" and applying it to a beverage derived from malted grain. It's also context-dependent, because I might be referring to the container (1) or the number of ounces (16).
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I have 2 rants. The symbol “/“ should be banned in schools. It only came back because students take notes with their laptops nowadays. The long horizontal line is better, ask any professor.
Second rant, people nowadays have developed how to title their post in a click-bait way.
Second rant, people nowadays have developed how to title their post in a click-bait way.
European here, 16, the way I (We) learned it, I had a 10 (A) for my math exam.
Been a few decades though.
Been a few decades though.
Whether one feels its ambiguous or not the equation is solvable as written.
The order of operation solves the ambiguity.
After the parens the rule is multiplication and division from left to right.
TheAppleFairy is right.
16
Signed,
BigTen-Pac12 non-math major who cheated in math every chance he got but still got this equation right. :smirk:
The order of operation solves the ambiguity.
After the parens the rule is multiplication and division from left to right.
TheAppleFairy is right.
16
Signed,
BigTen-Pac12 non-math major who cheated in math every chance he got but still got this equation right. :smirk:
It’s been a long while simple contemplated a formula like this but based on the answer the () signals division (complete formula- 4/4)? I was thinking the () part would have been multiplication in essence 4x4 or 4(4). What may have tripped me up was no /. I thought the () only signaled you carried out that function first before interacting with the rest of the formula.For grins and math giggles, see if you can find the correct answer.
8 ÷ 2(2+2) =