6:2(1+2)= Viral Math Problem Explained By Mathematician

#maths #math

[shaunpatrick]

The alleged ambiguity does not come from an archaic use of the division symbol, it comes from people applying PEMDAS to an equation which contains something which is not handled by PEMDAS. When you separate the juxtaposed terms and insert an operator so that PEMDAS rules can be followed, you change the equation and get the wrong answer.

[edeledeledel]

That is not the correct solution. You effectively inserted "X" when you included the dot in the expression. The expression 2(1+2) has not been properly expressed and has therefore not been fully resolved. The way it is written, it is logical to assume that the writer meant the expression to mean (2(1+2)) and you should do that first, to give 6. Then 6 ÷ 6 = 1, just a little bit different from 9..

Now, even if the expression was written 6 ÷ 2 x (1+2), it is still capable of misinterpretation, so should be written (6 ÷ 2) x (1+2) or 6 ÷ (2(1+2)), depending upon which was actually meant.

I am UTTERLY SICK of so-called mathematical experts writing ludicrously imprecise expressions; it encourages people to use imprecise expressions themselves. Misinterpretation of an imprecise expression can and has caused engineering disasters, with consequent loss of money and resources, possible ecological damage, and actual loss of life.

All for a couple of coppers from YouTube. You make me sick.

The very fact that you are posing this as a question shows quite plainly that it is easily capable of misinterpretation; whereas a properly constructed expression WON'T BE!

[richardslater]

These so called “viral” Pemdas “problems” are really annoying. It is up to the questioner to express the question in a way that is not ambiguous. Someone wouldn’t write “I saw the man with binoculars “ because that is ambiguous. You would write what you wanted to convey to avoid confusion. Same with maths. Pemdas is there only for social media.

[michi]

the verbal equivalent is: if you ask stupid questions you get stupid answers. this is by no means a viral mathematical problem. formulate the problem according to the rules of PEMDAS or define the rules people should apply to this expression.

[ThomasCole-nx]

2 is the coefficient of the term within the brackets. You cannot so easily separate them! to do otherwise woud create chaos in our international banking system.

[louf]

Ans = 1
The x(y) implies x times _the quantity of_ y. It's shorthand as described. Your method is when it is denoted with an "x" (elementary school) or a "." (dot).

[perryfarmer]

This really is not a change in order of operation. The obelus was first used in math in 1659. On page 76 of this book the obelus was demonstrated (example) as a vinculum. Its use as a vinculum yields the answer as one. When the book was published it was largely accepted in Anglophone countries. In Nordic countries the obelus was used for subtraction, in Russia for grouping (same as a vinculum, the original use). So when moving to 1917 using it as a shorthand vinculum is in fact in line with its original use.

[harrymatabal]

Mr Bigdog, you make the problem so simple. I don't see why all the fuss. Thanks❤

[jolantakrata]

6 : 2(1 + 2)
6 : 2(3)
6 : 6 = 1

6. 6
- - - -=--- = 1
2(3). 6
Checking result
1 × 6 = 6 output number

[carolweber]

I liked the way you explained the order. Whichever way we find the answer we must be consistent using premdas.

[mikestuart]

Here is a simple way that proves 1 is the ONLY ANSWER.
1. Find operators not in parenthesis = these are break points for the equation.
2. Break equation into segments. Put brackets around each segment.
3. Solve each segment.
4. Put them together.

6 / 2(1+2) = X
^ The only break point

[6] / [2(1+2)] = X Each segment is bracketed

6 / 6 = 1 Solve each segment and put them together.

Any method that does not yield 1 has serious flaws.

This method is not open to misinterpretation. This also proves this whole thing is a scam. One guy with over 20M views has made a ton of cash by claiming expertise and giving misinformation he stirs up controversy. One side is calling him over it, and then you have the sycophants yelling he is a mathematician, he knows. And although they haven't a clue, they rationalize all sorts of new rules. LOL
I think the guy must have made close to $500k by now.

[bigdog]

rewrite the division to multiplication by taking the reciprocal.

Problem is now 6 * 1/2(2 + 1)
Now we do inside the parenthesis which is (3)
Since all we have is multiplication it does NOT matter which goes first so lets do it as 3/2 * 6. that gives us 18/2 or 9.
Ok, what about 6 * 3 * 1/2 that is 18 * 1/2 which is 9

This proves beyond a shadow of ANY doubt that the order is PEMA or Parenthesis Exponents Multiplication then Addition. Or if you like the mnemonic Please Excuse My Dear Aunt Sally. Think of it as Please Excuse My Attitude.

(the removal of subtraction is done by using the rule x - y is the same thing as -y + x, and yes you can have a negative x and negative y value. IE -4 - 5 is the same as -5 + -4. The - sign is read as negative NOT minus)

[ΝίκοςΖαριφόπουλος]

Let me put a different problem: 6÷2÷3=?
I guess we all agree that the answer is =1. I don't think anyone would think to do the second division first. we simply perform the divisions from left to right. And ofc we all Know that (6÷2)÷3 is totally different from 6÷(2÷3). Also we can write 6÷2÷3=6*(1/2)*(1/3), this way there is no problem since a*b=b*a.
So when you see 6÷2*3 can you tell 6÷2*3=1=6÷2÷3 ??? Is there any reason to assume that multiplication takes precedence over division? Or why would anyone consider it as 6*(1/2)*(1/3)=1. The correct is 6÷2*3=6*(1/2)*3=9. So although it is not necessary, it is good to use parentheses to avoid misinterpretation, (6÷2)*3

[Kyrelel]

WRONG !!!!
PEMDAS is only the order of BASIC operations (+-*/) for children learning simple equations. Once they have mastered that, they learn other operations, many of which have a higher priority.
There is no multiplication symbol between 2 and (1+2), so it is NOT a BASIC operation (also, you used . which is actually a higher order than *)
The ONLY correct answer is 1

[AndrewMcMillan-gx]

Thnk of it like this

6×½×3= 9

Multiplication and Division are inverse operations.

6÷2 = 3

[clarasmith]

I do not agree with you. Take it up with my Math instructors

[thomassmith]

Because numbers can be multiplied in any order (the commutative rule of multiplication), multiplication takes precedence over division. Otherwise theb inconsistency allows for several different answers depending on the arrangement of the expression. 2(1+2) = (1+2)2 but then the answer by this new rule would be 4.

[DaleCretser]

Your explanation is WRONG and confusing for children

[teribeary]

Oh my goodness.... My dad and uncle knew B.O.D.M.A.S!!! I would come home from school and need help and they taught me this way and then Id go to school and get PEMDAS wrong!!! I'm 65 now and Thank you, thank you!!! BUT.... why did they change it??

[IanCarter-nc]

PEMDAS CRAP AGAIN! Rule number 1 is always use parentheses to avoid ambiguity!