Maths professor reveals the correct answer to the viral maths equation ‘8 ÷ 2(2 + 2)’

The entire internet has been divided over the answer to the viral maths question '8 ÷ 2(2 + 2)' because of the two apparently 'correct' answers that can be calculated, 16 or 1. The equation went viral with millions of people around the world arguing over which answer was more correct than the other. Maths expert Professor Keith Devlin, originally from California's Stanford University, is based at the University of Huddersfield while he completes a Leverhulme Visiting Professorship and we quizzed him about the equation. He reveals that in actual fact both calculations, 16 and 1, are both incorrect. Find out why in the video.

[seadrown]

My friends think it's 8 and it's honestly just sad 😂

[RealMesaMike]

Amusing to see so many commenters doubling down on a "correct" answer....

The fact is, there is diversity of opinion on what the expression actually means (or whether it's nonsense), even among academics and STEM professionals and insisting that there is an objectively correct answer is akin to bigotry...

[yassinelouchi]

The correct answer is 1, because according to the commutation law, multiplication takes priority over addition. However, it does not apply for the division which in this case is only the conventional version of the fraction. It is also necessary to pay attention to the fact that the distributive law takes priority over the commutative law. It goes from left to right for the "2 × (2 + 2)" part
8 ÷ (2 × (2 + 2))
= 8 ÷ (2 × 2 + 2 × 2)
= 8 ÷ (4 + 4)
= 8 ÷ 8
= 1
But as the professor already said, the way as the question is written, is false.

[RazerSCYNescafe]

like fresh air.... I knew it now... Thank you, professor!

[ssbsnb]

Can mathematicians just clearly define how to solve this problem, so we can end rhis debate!

[johng.]

the long lasting convention for 8/2(2+2) is that it is
8

2(2+2)
but that is implied, to make it explicit it should be 8/(2(2+2))
and for those that think it is 16, it should be (8/2)(2+2)

[robson_leao]

But what's the correct form of it?

[JolanXBL]

So the question is, how is this not an equation?

[daijirokatoh]

If in the US, math teachers can't give a precise response to this question, in France they can and the answer is 16

[fernandolino]

It's 1 to me because 2(2+2) still a factorization of 8. If you have an operación like 8÷2(2+2) Is not the same as 8÷2*(2+2) .

[Sean-vezt]

there is a way to solve the problem that is why the distributive property exists.. 8/2(2+2) Use the DISTRIBUTIVE property and the equation becomes 8/(4+4) ... 8/8 = 1.. if the distributive property did not exist then this equation would be problematic BUT since the DISTRIBUTIVE property does exist it makes this a solvable problem..

[doughendrie]

My take on it.
Mathway definitions of Term and
Quotient
Term
Any expression written as a product or quotient.
Example: 2xy, 4m²,
Quotient
The answer to a division problem.
8/2 cannot be used as the factor of (2+2)
As it is not a quotient. 4/1 or 4 is a quotient.
And the answer to 8/2.
So 8/2(2+2)
By the Distributive Law we get -
“The product of a multinomial by a monomial is obtained by multiplying each term of the multinomial by the monomial and adding algebraically the resulting products.”
2(2+2) 2 (mono) (2+2)(multi)
(2*2+2*2) Multiply
(4+4) Add
8 is the product of 8/2(2+2)
In accordance with Distributive Law
And Order of Operations.
8/8 Answer can only be 1

[Nunya_Business_]

Now we have the English opinion. Engineering shorthand in the US when I attended engineering classes. Not ambiguous.

[HDitzzDH]

People are still trying to answer the question, just give up people lmao. The question was intentionally poorly written to cause a debate, and you guys certainly made it viral, it's not a serious problem whatsoever. It's ambiguous by definition so let's just move on.

[mickmaidens]

This would have been better if he had shown the correct mathematical grammar for both answers. His answer is vague.

[steelea]

Tf why do people need a math prof to tell them the answer to a simple equation

[Of_UnCommon_Sense]

There is a very easy way to do this.

There are several paths to 1 as the only correct answer. But this is the easiest.

For those long and difficult equations we normally break them into segments.

Splitting this terribly complicated equation into segments, is a method that is INCONTROVERTIBLE.

[Look for explicit operators not enclosed in brackets, then put brackets around each segment.]
There is only the divisor. This simplifies and clarifies this long and tedious equation.

i.e. 8 / 2(2+2) -> [8] / [2(2+2)]

Now we clearly see it is 8 / 8 = 1
For people who do not understand parenthesis, this avoids the silly question of what to do 1st.

[Atistatic]

Yeah well ... when you propose an mathematics objects as an Abelian Groups how to do it ? Division aren't commutative and might not have an inverse element.

[dylans_vibeschannel]

It’s indeed 16.
Always start with the parentheses ()=2x2=4
Then divide. 8/2=4 */ is mainly used for the division symbol because the symbol is not on the keyboard just a disclaimer*
Now, ik what your thinking, there’s no symbol to add or multiply wtf do we do?? Well, when this happens, you multiply because Multiplication comes before Division, look, PEMDAS. M which is multiplication comes before D which is division. “Please Excuse Multiplication (My) Division (Dear) Aunt Sally”. I let ‘em rats talk, so if y’all rats wanna talk in my reply section, go ahead, I ain’t stopping you.
So, 4x4=16!
Like this comment if you got 16 a different way and please explain it by replying. Thank you!

[reactionlessssbu-clips]

you are wrong 16 is the wrong answer because of the very first step of the equation which eliminates the possibility of having 16 as the answer 8/2(2+2) should not be 8/2x4 yes it is a correct answer but we only made that because it is easier for ourselves to be lazy but the proper order was not used correctly

brackets have the highest priority but what has higher priority among what can be applied to the bracket? multiplication or addition?
it's multiplication and to support that 8/2(2+2) should be 8/(4+4) because we are solving the bracket from left to right another reason why it should be prioritized

so it goes like this
8/2(2+2)
8/(4+4) we are solving the bracket with the priority that we are going left to right and multitiplication before addition
8/8 we solved the bracket
=1
no where with this proper ruleset and proper thinking does it show a hint that 16 can be a possible answer you must always remember not do each rule 1 by 1 because all rules applies to what you are doing
brackets
exponents
division
multiplication
addition
subtraction
Bedmas the bracket solving als0 relies on bedmas this is the critical meta thinking we should remember