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

Nobody:

Mind your decisions:viRal iN jApAN

I did it in mind

reaaaaaaaally! This is so basic mathematics

Without watching ik that the answer is 0.99999r

who else got 1?

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

Step

3÷1/3=9

9-9=0

0+1

=1

Iam form USA guys

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

I did true

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

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

One: the loneliest number. ?

Literally solved it in 2 seconds

This is easy

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

19

I guess there’s another way 3(9-3/ 1/3 +1)

27-9/1+1

18+1=

19

This is easy

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.

1

I solved it before i even clicked on the video

1

8

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

I got it

1

1……………………………………. the answer is 1

1

Yeah I got the right answer

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

9➖3➗(1/3)➕1

=9➖3✖3➕1

=9➖9➕1

=0➕1

=1

Its just applying BODMAS rule

Is 1

Correct answer is 1

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

1

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

Lol

1

?

Ye!??

BODMAS

B-BRACKET()

O-OPERATOR

D-DIVISION

M- MULTIPLY

A-ADDITION

S-SUBTRACTION

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

Its -1 not 1

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

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

4.9t^2+30t-20=?

Easy

1

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.

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

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

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

Bruh

How do you get this wrong?

Solved in 5 seconds 🙂

I think it's 1

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.

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

I thought answer 19

Sorry my answer is wrong

0:20 OK BOOMER

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.

Three divided by one third=

Three time three

l。

1

The answer is 1 that's easy

1

reform 1/3 to 3^-1 then mdas

reform 1/3 to 3^-1 then mdas

Did anyone salve it by looking at the thumbnail

Simply take reciprocal to divide.

Answer is 1 or am i tripping

3÷ 1/3

Is same as

3 × 3

Yea!

Easy

Bruh that was so easy lol

Easiest problem ever

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

Baby can do this

(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)

I am only 11 yrs but I figured it out

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.

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

2:48

I heard him stumble in his video for the first time

It's not even a mistake

In some countries they use the same as the first problem

Bedmas*

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

Bro that was an easy question

1

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

9

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

If

*MDAS*:7

*IF LEFT TO RIGHT*:3

This was easiest question asked on ur channel..

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

9-3×3+1=9-9+1 =1 easy

Eyyyy my answer is correct?

Give a Dislike plz that macks me happy

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……

1

easy

1 in photo math

yeah im correct