Math for cf.neters

[Claudya]

Awww, poor Classik. :smt056

Would you prefere a different result?

 

[Classik]

Why are we so divided over such a seemingly difficult math?:dunno

 

[Classik]

Is spreadsheet a clue? Is it a standard? How does it solve this problem??? Try this using MS Excel. Is the answer provided by MSE correct? :dunno Just input the characters exacty the way they appear on MSE. Do not give spaces. But is such an answer a valid one?

 

[WIP]

Okay, I spent the last couple hours or more searching the internet for any information in support of thisnumberdisconnected and I came up completely empty. I found no support at all. Until now, I personally have never heard of anyone employing the same rule as thisnumberdisconnected. In my 20 years of working with industrial control and servo systems along with their various programming software I have never experienced a single system that does not employ the PEMDAS rule. In fact, it is when I neglect to apply the rule that I have put myself into trouble.

As another test, I entered the expression =(5+4*3-2) into a Microsoft Excel cell and the answer returned was 15, not 25 as would happen following the rule of thisnumberdisconnected.

I used the same expression to calculate an offset in my CAD software and it applied the value 15, not 25.

I know for a fact that our team of nearly 150 mechanical and electrical engineers and designers (some with PhD’s in engineering, physics, or chemistry) all use the PEMDAS order of operations rule.

Here are a few of the references I found in my online search. My search criteria was “Mathematical order of operations for engineers†and “College math order of operations.â€

H. Wu, emeritus professor of mathematics, University of California, Berkeley puts it this way: “exponents first, then multiplications and divisions, then additions and subtractions.â€

According to the SOPHIA standards applied at Capella University in Minneapolis, MN the correct order of operations is PEMDAS.

According to Noel Molloy the order is PEMDAS. His credentials: BSc in Applied Physics/Electronics, Specialized Diplomas in Medical Device Design and in Lean and Six Sigma Quality Science, Six Sigma Green Belt and a Masters in Business Administration backed up with 28 years supervisory and engineering experience in locally based multinationals (APC and Nortel).

According to TutorVista, the world's leading online education company with its diverse and highly educated tutor base of over 2000 teachers spanning India, United States, UK, Australia, China and South East Asia, the correct order is PEMDAS. The Company has grown rapidly with over 5 million online sessions served to students worldwide.

According to C++ programming standards PEMDAS is the order. http://www.cplusplus.com

One final note. In defense of thisnumberdisconnected, I did find one document here, http://www.math.vanderbilt.edu/~schectex/commerrs/ that did indicate there are some variations in the rule of order and in some cases these variations can cause problems. A simple example was when the expression 2^3^4 was entered into both a TI85 and TI89 calculator the results were different. In the TI85 it solved it this way (2^3)^4 however in the TI89 it solved it this way 2^(3^4), demonstrating that even within the same manufacturer the engineers don't agree.

It would seem there is some inconsistency in the math world but in my research the overwhelming majority use the PEMDAS rule.

 

[thisnumbersdisconnected]

It would seem there is some inconsistency in the math world but in my research the overwhelming majority use the PEMDAS rule.

Again, the rule of thumb at just about every level of mathematics usage is, if it isn't in the proper form to apply PEMDAS, you don't use PEMDAS. I think the eduators are out of touch with reality. If they attempted to use PEMDAS in a math function that was not formatted with parentheses and functional guidelines, they'd be wrong, and in the design of an airframe, for example, that would be disastrous.

Work the formulas presented as written. It is a must, a "have to." Doing otherwise is absurd.You have to have "road signs" and those road signs in math are the proper format, which must be obeyed if everyone is to come to the same conclusion on a given math function. You can't apply formatting rules to equations that are not written with a format. Period. It's ridiculous to say otherwise.

 

[Classik]

So what should we really teach students???

 

[WIP]

Again, the rule of thumb at just about every level of mathematics usage is, if it isn't in the proper form to apply PEMDAS, you don't use PEMDAS. I think the eduators are out of touch with reality. If they attempted to use PEMDAS in a math function that was not formatted with parentheses and functional guidelines, they'd be wrong, and in the design of an airframe, for example, that would be disastrous.

Work the formulas presented as written. It is a must, a "have to." Doing otherwise is absurd.You have to have "road signs" and those road signs in math are the proper format, which must be obeyed if everyone is to come to the same conclusion on a given math function. You can't apply formatting rules to equations that are not written with a format. Period. It's ridiculous to say otherwise.

So are you suggesting that you're right and the rest of the world is wrong? I know for a fact that if I applied your formula I would fail miserably in my field, hands down. And with that, my hands are down.

 

[Classik]

BODMAS VS PEMDAS

 

[tim-from-pa]

Not in the world of engineering, and I'm 99.99999% certain that world isn't any different than other higher mathematics. What students are being taught in middle- and high school is contrary to the way the rules of math are followed in the real world where math actually matters.

Putting these numbers in just the way the problem is stated into the Texas Instrument TI 30X IIS Engineering calculator, or the Windows 7 Microsoft calculator ver 6.1, or even the calculator I use here on my Linux machine Kcalc ver 2.11 all yield 20 as the answer.

Perhaps you can email all these companies or software creators and tell them why 99.99999% of everyone else in the real world gets 320 like you did. Then when you convince them of your remarkable accuracy, let us all know how you fared. Best of luck. :

 

[tim-from-pa]

Why are we so divided over such a seemingly difficult math?:dunno

I don't think we're all that divided.

Most got the proper answer 20, as you stated (and there's no need to take a poll with mathematics anyway as I stated earlier)

The rest that got it wrong, probably admit to it, suck it up, and move on. No debate. Nothing wrong with that.

There there's one that keeps insisting PEMDAS is not used when articles, forum quotes, calculators and all sorts of evidence like that state to the contrary. I can sort of see that view in religion where things are subject to interpretation, but mathematics with defined rules are created just for that, so there's not many interpretations. But when something this clear cut is denied, it actually starts to become worrisome as to what else can smack in one's face and still be denied?

 

[Classik]

That was a joke. I was being light-hearted

 

[MathGuy]

I concur that the answer is 20. I'm currently majoring in math, and I would be shocked if there were any field in which the answer was not understood to be 20. (However, thisnumbersdisconnected does have more exposure to other fields than I do.)