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9 – 3 ÷ 1/3 + 1 = ? The Correct Answer (Viral Problem In Japan)

December 23, 2019


Hi, this is Presh Talwalkar Can you solve this problem which went viral in Japan? A recent test found that only 60% of Japanese 20 year olds were able to get the correct answer This is alarming, because it is down from 90% – which was the accuracy rate in the 1980s Can you figure it out? To get started, I´m going to over a common mistake Many people will input this expression into Google or into a calculator In order to do so, you have to convert the fraction 1/3 into an inline expression Many people write out the equation in the following form Now, you will interpret 1/3 as being grouped together However I will discourage you from writing expressions in this form It is not clear that the 1/3 should be grouped together – – because this expression using both the division symbol and the division slash – – which are the same mathematical symbol of division Although you want the 1/3 to be grouped together – – this expression is going to be evaluated by a calculator – by converting this division symbol into a division slash This will NOT be equal to the original expression The calculator is going to look at the 3 divided by 1 divided by 3 as one term and it is going to evaluate it from left to right Now a calculator would properly evaluate this 1/3 it´s going to evaluate the 3 divided by 1 first, – then it is going to divide 3 divided by 3 – and then it is going to do 9 minus 1 plus 1, which will give you the result of 9 If you were to transcribe it on a calculator – you want to make sure that the fraction of 1/3 maintains grouped together So instead of writing THIS expression – – you would like to write an expression which GROUPS the 1/3 as one group Now a calculator will properly evaluate this 1/3 – and this whole term: 3/(1/3) in a proper order 3 divided by (1/3) is equal to 9 – and now we have 9 minus 9 plus 1, which give us the correct answer of 1 The problem is a good reminder of the order of operations These can be remembered by the acronyms PEMDAS or BODMAS These relates to the order of operations of Parenthesis or Brackets – Exponents / Orders – then Multiplication – Division – and finally Addition – Subtracton Another important rule, is that if you have – – operators of the same precedence – – you want to evaluate the expressions from left to right So let’s get to that We have no parentheses or brackets in this expression, we also have no exponents or orders We do have a division here, which is 3 divided by 1/3 So let’s evaluate this first – 3 divided by 1/3 is the same thing as 3 multiplied by the reciprocal of 1/3 which is 3 We now has a multiplication of 3 times 3 – – which we also evaluate before anything else 3 times 3 is equal to 9 And now we have an expression with only addition and subtraction So how do you evaluate this expression? How do you know what to do? If you have something of the same precidence – addition and subtraction – you want to evaluate the expression from left to right So our first evaluation of 9 minus 9 which gives us 0 – then you evaluate the 0 plus 1 which gives us the correct answer of 1 Did you figure it out? Thanks for watching this video and please subscribe to my channel I make videos of math and game theory You can catch me on my blog MindYourDecisions which you can follow on FaceBook, Google+ or Patreon You can catch me on social media as @preshtalwalkar And if you like this video, please check out my books – there are links in the video description.

100 Comments

  • Reply Mr Murica November 6, 2019 at 5:47 am

    Nobody:

    Mind your decisions:viRal iN jApAN

  • Reply BenGBenMC November 6, 2019 at 3:19 pm

    I did it in mind

  • Reply iam_ ikram__ November 6, 2019 at 5:32 pm

    reaaaaaaaally! This is so basic mathematics

  • Reply Vortex _YT November 6, 2019 at 8:45 pm

    Without watching ik that the answer is 0.99999r

  • Reply shelbrique November 7, 2019 at 1:27 am

    who else got 1?

  • Reply Robert Gammett November 7, 2019 at 8:24 am

    Japan uses common core math, makes sense. But it’s 9(-3/.3)+1=9-9+1=1

  • Reply peace good November 7, 2019 at 10:18 am

    Step
    3÷1/3=9
    9-9=0
    0+1
    =1
    Iam form USA guys

  • Reply Duy Anh Nguyễn November 7, 2019 at 11:04 am

    How the hell this equation became viral it's basic maths

  • Reply Emre Koc November 7, 2019 at 5:21 pm

    I did true

  • Reply Mati Ramírez November 7, 2019 at 8:15 pm

    Hay q ser demasiado pelotudo para equivocarse así, este es un problema que tranquilamente se puede dar en la escuela primaria

  • Reply WolfTrain Games November 7, 2019 at 8:46 pm

    Guess I'm the only one who failed math all throughout school.. XD I have 0 clues.

  • Reply Albert Zayha November 9, 2019 at 7:42 am

    One: the loneliest number. ?

  • Reply Scipio November 9, 2019 at 10:17 am

    Literally solved it in 2 seconds

  • Reply Finn Nelson November 9, 2019 at 5:50 pm

    This is easy

  • Reply Stephen Drummer November 9, 2019 at 11:39 pm

    How about using parentheses to declare the desired order of operation?

  • Reply Vijay Nair November 10, 2019 at 7:08 am

    19

  • Reply Daily Dose Of Cubing November 10, 2019 at 2:19 pm

    I guess there’s another way 3(9-3/ 1/3 +1)
    27-9/1+1
    18+1=
    19

  • Reply That Cuber tho November 10, 2019 at 4:35 pm

    This is easy

  • Reply lynn rathbun November 10, 2019 at 6:01 pm

    Arguing about how to interpret a badly structure expression is like arguing about interpreting a poorly constructed sentence. The invented commas and parentheses for a reason. USE THEM. Otherwise you are just asking for trouble.

  • Reply Shadow Vojta November 11, 2019 at 4:45 pm

    1

  • Reply Noel Döme November 11, 2019 at 10:40 pm

    I solved it before i even clicked on the video

  • Reply Las Kerfuffle November 12, 2019 at 12:55 am

    1

  • Reply Yolo Swag November 12, 2019 at 11:06 am

    8

  • Reply Movie Scenes November 12, 2019 at 2:21 pm

    The answer is 1. Lol it took me only 15sec

  • Reply Alex November 13, 2019 at 7:18 am

    I got it

  • Reply Sanjib Pramanik November 14, 2019 at 5:32 pm

    1

  • Reply SKL# llamalover November 15, 2019 at 1:20 am

    1……………………………………. the answer is 1

  • Reply sulochna Bura November 15, 2019 at 5:00 am

    1

  • Reply Manash Jyoti Barman November 15, 2019 at 11:57 am

    Yeah I got the right answer

  • Reply GamerBrine101 November 15, 2019 at 6:15 pm

    Yet another instance of retards not understanding one of the basic principles of math and making something seem more difficult than it really is

  • Reply Wilson楊浩銘 November 16, 2019 at 1:49 am

    9➖3➗(1/3)➕1
    =9➖3✖3➕1
    =9➖9➕1
    =0➕1
    =1

  • Reply Geetha Venkat November 16, 2019 at 3:02 pm

    Its just applying BODMAS rule

  • Reply Diablo the Demon November 16, 2019 at 10:10 pm

    Is 1

  • Reply Mrx Wolfhard November 16, 2019 at 11:31 pm

    Correct answer is 1

  • Reply BeastBeatsGaming MLG November 17, 2019 at 9:22 am

    Actually the answer is -1.
    9-3÷(1/3)+1
    =9-(3×3)+1
    =9-9+1
    According to BODMAS, addition comes before subtraction. Thus this is the result
    9-9+1
    =9-10
    =-1

  • Reply Jagan Chinna November 18, 2019 at 5:03 am

    1

  • Reply Lohvitskii Mapper November 18, 2019 at 6:37 am

    блять, это задачка третьего класса, какого хуя ты называешь это ПРОБЛЕМОЙ МАТЕМАТИКИ сука!?

  • Reply sanyam verma November 19, 2019 at 5:29 pm

    Lol

  • Reply rafe lemay November 20, 2019 at 3:56 am

    1
    ?

  • Reply rafe lemay November 20, 2019 at 3:58 am

    Ye!??

  • Reply Arjot Singh Gill November 20, 2019 at 8:45 am

    BODMAS
    B-BRACKET()
    O-OPERATOR
    D-DIVISION
    M- MULTIPLY
    A-ADDITION
    S-SUBTRACTION

  • Reply Kevin Hernon November 20, 2019 at 5:08 pm

    Why do people need calculators for this? I’m in 6th grade and I can do it off the top of my head.

  • Reply Junaid's Channel November 20, 2019 at 6:18 pm

    Its -1 not 1

  • Reply Anthony Holland November 21, 2019 at 1:57 pm

    I just turn it into a decimal, .3333333 and got my answer

  • Reply KODE SOLUSI November 22, 2019 at 12:16 am

    its more harder if you used calculator. you must on it then type the number oroperation. even you can get the answer with imagine thenumber witout any tools.
    why japan do it ? japaan must be an asiaanss, theyare cando anything :v

  • Reply Unique Boruah November 22, 2019 at 2:51 am

    4.9t^2+30t-20=?

  • Reply Pragyan Raturi November 22, 2019 at 7:28 am

    Easy

  • Reply Šįř Hīťľĕŕ November 22, 2019 at 8:15 am

    1

  • Reply Allen Anderson November 22, 2019 at 2:46 pm

    Have you noticed that just about ALL of these viral math problems have the ÷ (obelus) in them?
    This is the main point of contention. The historical meaning of that symbol is to divide everything on the left side of it by everything on the right side of it.
    When dealing with just numbers, then the obelus and the / symbol do the same thing.
    Over time, the obelus has come to mean the same thing as / regardless of what the expression is.
    In my opinion, there should be only one symbol for division and always use parentheses to show exactly what is intended, otherwise these pointless discussions will continue ad infinitum.

  • Reply Timothy Phipps November 22, 2019 at 8:26 pm

    I'm a highschool drop out and math was not my strong suit but I got it. PEMDAS (Please Excuse My Dear Aunt Sally)

  • Reply Icy Glacier November 23, 2019 at 5:17 am

    Uh what?No offense Japanese but what the ACTUAL heck?

  • Reply Aayaan Shaikh November 23, 2019 at 1:52 pm

    Answer is -1 by bodmas rule
    9-3[1/3]+1
    =9-9+1
    As per bodmas we have
    9-10
    = -1
    This is the answer bro

  • Reply The lamb sauce November 24, 2019 at 5:00 am

    Bruh
    How do you get this wrong?

    Solved in 5 seconds 🙂

  • Reply MC Empanadas November 24, 2019 at 10:17 am

    I think it's 1

  • Reply Jean-Francois Bouzereau November 24, 2019 at 11:23 am

    The order of operations has to do with programming languages, not mathematics! The natural way of computing the expression for a layman would be from. left to right : 9-3 = 6 , divided by 1/3 = 18 , plus 1 = 19.

  • Reply S H November 24, 2019 at 9:18 pm

    Answer is = 1 — use RPN (reverse Polish notation) calculator… like a HP ((Hewlett-Packard ) good luck!

  • Reply Ranjan Srivastava November 25, 2019 at 6:01 am

    I thought answer 19

  • Reply Ranjan Srivastava November 25, 2019 at 6:03 am

    Sorry my answer is wrong

  • Reply יעקב מכלוף November 26, 2019 at 5:37 am

    0:20 OK BOOMER

  • Reply Anthony Martin November 26, 2019 at 5:55 am

    this is why you should not use a combination of dividing symbols, and should either do it entirely inline using brackets or with the horizontal line, not both.
    Because it is unclear as it is whether you are dividing by a 3rd or dividing by 1 then 3.

  • Reply Ernie Cheng November 26, 2019 at 11:07 am

    Three divided by one third=
    Three time three

  • Reply kwokyan chung November 27, 2019 at 7:54 am

    l。

  • Reply Venkatesh Kumbam November 27, 2019 at 8:57 am

    1

  • Reply ONESWORD MĪXtube November 28, 2019 at 5:01 am

    The answer is 1 that's easy

  • Reply Jayso Ng November 28, 2019 at 1:33 pm

    1

  • Reply Asriel Cyle Oroceo November 28, 2019 at 10:52 pm

    reform 1/3 to 3^-1 then mdas

  • Reply Asriel Cyle Oroceo November 28, 2019 at 10:53 pm

    reform 1/3 to 3^-1 then mdas

  • Reply Alexis Ultimanium November 29, 2019 at 3:43 am

    Did anyone salve it by looking at the thumbnail

  • Reply VIKRAM VARDE November 29, 2019 at 8:30 am

    Simply take reciprocal to divide.

  • Reply Matthew Curiel November 29, 2019 at 10:16 pm

    Answer is 1 or am i tripping

    3÷ 1/3

    Is same as

    3 × 3

  • Reply Amanda McDonald December 1, 2019 at 8:28 am

    Yea!

  • Reply Royer Paul Canasa Sucasaca December 1, 2019 at 5:22 pm

    Easy

  • Reply Lindi Lp December 2, 2019 at 5:29 am

    Bruh that was so easy lol

  • Reply Zainab Shaikh December 2, 2019 at 4:09 pm

    Easiest problem ever

  • Reply technology of honour t o h December 3, 2019 at 11:29 am

    Wtf……9-9+1=-1 not 1, according to bodmas

  • Reply technology of honour t o h December 3, 2019 at 11:32 am

    Baby can do this

  • Reply 빠끄 빠끄 December 3, 2019 at 1:11 pm

    (I’m a Korean so English is a second language for me.) Can anyone explain what this problem means?(I know how to play but I can’t understand why many people think this is hard)

  • Reply Kasturi Warudkar December 3, 2019 at 3:48 pm

    I am only 11 yrs but I figured it out

  • Reply Rudolphhhhhh December 4, 2019 at 9:43 am

    The correct answer is indeed 1. However, I disagree with the last rule "If same precedence, left to right" : not at all, this is not a rule ! If we have the same precedence, then it is possible to permute the analog operations. So we can calculate "-9 + 1", which gives us "-8", and then we calculate "9 – 8", which is equal to 1 (but in that situation, it is true that it is easier to calculate from left to right). Sometimes, permuting analog operations can make a calculation easier. For example, let us consider the calculation "5 – 7 + 4 + 7" : ok, we can calculate from left to right, but it is not the smartest thing to do. It is better to calculate "-7 + 7" at first, which gives us 0, and then calculate 5 + 4 = 9". It is for that reason that we can simplify fractions, as "12 * 14 / 28" : calculating "12 * 14" at first is not the smartest and fastest way to calculate, so it is much better to calculate "14 / 28" at first, which gives us 1/2, and then calculate 12 / 2, which is equal to 6.

  • Reply Leo Messi December 4, 2019 at 1:39 pm

    And soon in future,,, scientists will try solve 2+2=?

  • Reply Bhupinder Kaurhut December 6, 2019 at 9:30 am

    2:48
    I heard him stumble in his video for the first time

  • Reply Poowarrior Games December 8, 2019 at 11:53 pm

    It's not even a mistake
    In some countries they use the same as the first problem

  • Reply Vishal Mahabir December 9, 2019 at 10:00 pm

    Bedmas*

  • Reply トマト December 10, 2019 at 10:15 am

    Hello, i'm going to second grade in highschool and i forgot everything ?

  • Reply MD Sani December 11, 2019 at 5:33 am

    Bro that was an easy question

  • Reply Mr. Kipod December 11, 2019 at 5:54 am

    1

  • Reply 진검곤 December 11, 2019 at 6:20 am

    well how many people did it in their head in 3 sec this is just a simple grade 2 or 3 math problem in my country

  • Reply Ultra Gamer December 12, 2019 at 2:12 pm

    9

  • Reply Denis Tezza December 13, 2019 at 12:32 am

    I solved it in few seconds and i am very far from being a math genius. Is it a joke?

  • Reply Sw3GGam3r December 13, 2019 at 9:36 am

    If
    *MDAS*:7
    *IF LEFT TO RIGHT*:3

  • Reply Shruti Dhapare December 13, 2019 at 12:54 pm

    This was easiest question asked on ur channel..

  • Reply Devanand Sahu December 13, 2019 at 3:16 pm

    I thought it will be difficult n challenging but it disappointed me

  • Reply Angel Melendez December 15, 2019 at 2:37 am

    9-3×3+1=9-9+1 =1 easy

  • Reply Clifford Vidal December 16, 2019 at 4:22 am

    Eyyyy my answer is correct?

  • Reply Mousa Alalbnani December 16, 2019 at 10:36 pm

    Give a Dislike plz that macks me happy

  • Reply 飛躍キツツキ December 18, 2019 at 3:07 pm

    この程度の問題が六十%の大人にしか解けないというのは危険だな……

  • Reply The Nicollas December 18, 2019 at 6:52 pm

    1

  • Reply LidleVolkan December 19, 2019 at 9:07 pm

    easy

  • Reply Syauqi Mubarok December 20, 2019 at 3:19 am

    1 in photo math

  • Reply 풍뿌잉 December 22, 2019 at 1:48 pm

    yeah im correct

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