# Solve This Simple Math Problem

It’s Friday. Let’s have a little fun.

Solve this simple math problem. No Googling.

### 115 Responses

1. someone like you

08/28/2013, 09:25 pm

so easy it took me three seconds to look at the problem and 4 seconds to solve and 15 seconds to show my work the answer is 20.
problem: 4×4+4×4+4-4×4
4x4x2=16×2+4=36
here is where pemdas helps u figure and u have to pay close attention the last 4×4 has a – sign in front of it so that is -16
36-(-16)=20

• someone unlike you

09/06/2013, 01:10 am

should have spent a little extra time showing your work there bud. because with what you have shown, 36-(-16), the answer would not be 20, but 52 because that “reads” 36 minus a minus 16. surely what you meant to show was 36+(-16) or simply, 36-16 which btw has nothing to do with pemdas. your pemdas was just solving the multiplication before the addition.

2. Pan the Man

09/21/2013, 02:31 am

20 Do multiplication first so it is now 16+16+4-16=? well two 16’s will cancel out so now we have 16+4=? so ?=20 20 is the only solution there is no square root or imaginary numbers. It is just 20

3. rationality&reason

03/22/2014, 01:11 am

The real problem here is with the question, and I submit as evidence that, apparently, “73% of people failed to answer this”. This issue touches on one of my favourite rants, so… brace thyself:

To solve this problem, we are required to know one of the most useless pieces of knowledge ever developed by human kind: a protocol for eliminating ambiguity from a statement where, if the author of the statement was not a sociopath, there would have never been any ambiguity in the first place. That’s right, we need to know the “order of operations” to be able to see which tasks need to be done before others. Why would anyone in their right mind create such a statement, when all that is required is the appropriate application of a single tool to clarify that actual intent. The tool is brackets, my friend, and if you care about the person who reads/parses/uses that which you create, please use them.

Let’s do another test: find out how many people can answer this question:

? = (4 x 4) + (4 x 4) + 4 – (4 x 4)

Then, let’s use the data to infer if the problem is with the math skills of the population, or with the communication skills of the question’s author.

I have programmed software for most of my life, and in this domain the “order of operations” logic can become hugely more complicated than that of simple mathematical operations. Those who rely on the stated “order of operations” logic for complex (or even simple) statements create confusion, undermine maintainability, increase costs and fragility. They may even increase danger: the airplanes you fly on have a lot of software between the pilot’s hand and the control surfaces.

So, let’s stop teaching people useless disambiguation protocols, and instead teach them how to communicate clearly.

4. Evan Snyman

04/09/2014, 09:43 pm

I much prefer de Jager’s 3-step method to any of the BODMAS variants – brackets, terms, work from left to right… It actually empasises a mathematically important concept – terms – rather than just being a gimmicky algorithm.

5. Mayz Edwardson

04/10/2014, 12:46 am

That is so simple. As soon as I looked at it I knew the answer. Four multiplied by four is sixteen, so you’d have sixteen plus sixteen plus four subtract sixteen. Sixteen plus four equals twenty, so you’d have sixteen plus twenty subtract sixteen. Twenty subtract sixteen equals four, so you’d have sixteen plus four. SIxteen plus four equals twenty, so the answer is twenty. Somewhat complicated to explain but easy to figure out in your head.
Steps: 4 x 4 + 4 x 4 + 4 – 4 x 4
16 + 16 + 4 – 16
16 + 20 – 16
16 + 4
20

• Mayz Edwardson

04/10/2014, 01:47 am

Well the hypotenuse is 5, by the pythagorean theorem (a^2+ b^2 = c^2) other two legs are 4 and 3. The angle between 4 and 5 we will call angle 1, and the angle between 3 and 5 we will call angle 2. The third angle is of course 90 degrees.
If we want to find angle 1 (formed by 4 and 5) we place pheta (ÆŸ) in that angle. We do this so we can find the oppisite and adjacent sides. Side 4 is adjacent because it helps form the angle. Side 3 is oppisite because it doesn’t touch the angle. Side 5 is important too, but we don’t need pheta to find out what it is, because side 5 is the hypontenuse (it doesn’t form the right angle).

Now you can find Sine, Cosine, or Tangent. It doesn’t matter which because you will get the same answer any way. For angle 1 I chose to find the Sine. To find Sine you divide the oppisite side by the hypontenuse. To find Cosine you divide the adjacent side by the hypontenuse. To find Tangent divide the oppisite by the adjacent side. This is often remembered by SohCahToa or:

Sine
Oppisite
Hypontenuse

Cosine
Hypontenuse

Tangent
Oppisite

The sine of pheta (while on angle 1) is 3/5, as shown below. To solve for pheta (the measurement of the angle) You simply reverse the sine. This is harder to explain and easier to show so just look below. Then you have your measurement for angle 1. To solve for angle 2, just do the exact same process, but with pheta on angle 2.

Angle 1: Sin ÆŸ=(3/5)
So, ÆŸ= Sin-1(3/5)

Just plug this into your calculator…

Angle 2: TanÆŸ = (4/3)
So, ÆŸ= Tan-1(4/3)

Angle 1 = 36.86989765 degrees

Angle 2 = 53.13010235 degrees

Angle 3 = 90 degrees

All added together equals 180 degrees

Also, angle 1 and 2 are complimentary so they add up to 90 degrees.

And you thought both angles were 45 degrees.

• Mayz Edwardson

04/10/2014, 01:49 am

It’s longer than I thought it was. hahaha lol

6. gb88

07/04/2014, 04:55 am

The answer is 20! ( I did it in my head, while falling asleep). They probably tested 2nd graders. That’s why 73% of people failed to answer this very feasible question.

7. Smartalex

08/07/2014, 01:53 am

He said failed to answer because 73% are not Mathaholics and don’t care about the problem and by the way the answer is 20 not 320 use basic math rules people

8. Tyler Toole

08/18/2014, 02:34 pm

4×4+4×4+4-4×4 = x

Step One: Honor Pemdas
(4*4) + (4*4) + (4) – (4*4) = x

Step Two: Organize Processes As Desired
(4*4) + (4*4) – (4*4) + (4) = x

Step Three: Simplify Tasks / Don’t do any work you don’t have to.
(4*4) + (4) = x

Step Four: Loose Unnecessary Emphasis On Assumed Principals
4*4+4 = x

Solve: 20 = x

73% of people are offended to apathy by the sloppy presentation of your “problem”.
>No googling.

9. MJSee

03/13/2015, 04:53 pm

This is why 73 % of the people get this wrong. They apply Bedmas/Pedmas when it shouldn’t be applied. Simple math problems like the one above does not require bedmas. The rule for simple math is to do it from left to right unless there are brackets in the formula. Then you do the brackets first, then left to right. There are no brackets in this. You don’t magically put in brackets to make your math work. It’s a simple left to right.

Bedmas comes from scientific calculators vs simple ones. The reason for the two types is because of the intended usage. The scientific ones have higher math programing functions which include bedmas.

The simple function ones don’t, and that is simply because they are meant to be used for simple math problems like the one above.

Look at the windows calculator. The standard one gives you straight left to right answer. Switch it to the scientific one and do the formula and it will apply Bedmas.

This is why there is so much confusion.

4×4+4×4+4-4×4= 320 (Standard Calculator)
4×4+4×4+4-4×4= 20 (Scientific Calculator)

The more complicated math formulas require a scientific formula and bedmas applies.

The one above doesn’t require it. So anyone who said 20 is incorrect.

• keepinitreal

04/08/2015, 12:48 pm

I agree with every thing you said except the correct answer. , why would you say 20 is correct? the opening states “solve the simple math problem” . There is no mention of algebra so the correct answer would be 320. This is why 73 % get it wrong.

10. keepinitreal

03/22/2015, 02:04 pm

The head line says ” solve this simple math problem” not ” solve using BEDMAS” why are we all using BEDMAS. simple math implies using order of sequence.. which would make the correct answer 320. bedmas don’t work in every day calculations and I was taught both BEDMAS (order of operations) and order of sequence. its when to use which one that appears to be a common problem. I will give a simple example where bedmas don’t work .you bought 10 tires from london next day you bought 4 from caledonia then you sold them all for \$80 each. order of sequence 10 +4*80 =1120 bedmas 10+4*80=330 Problem solving requires more information, not just numbers on a page. Had it said solve the scientific equation or something to lead us to believe it was any thing other than simple math then I would use BEDMAS.

• keepinitreal

04/08/2015, 01:04 pm

first of you don’t know me , so keep your insults to your self. Secondly, BEDMAS has no application in retail as I illustrated above.. There is no mention of algebra , it states ” solve the simple math problem” Simple math is solved with order of sequence. Had it said solve the algebra problem, or the scientific problem, you would use BEDMAS.
For those who cant see (simple math) 10 tires + 4 tires sold for 80 each = 1120
Bedmas 10 tires + 4 tires sold for 80 each 10+4X80 =330
BEDMAS if used in simple math problem will give the wrong answer order of sequence gives the right answer. this is why 73 % get the wrong answer when it says solve this simple math problem.