# Which calculator?



## Katiebug (Feb 12, 2008)

So I was perusing the allowed calculators list on the NCEES website and was giving thought to what I want to use, since my regular calculator is definitely not allowed, and I want to study with a calculator I can actually use for the test.

_Casio: All fx-115 models. Any Casio calculator must contain fx-115 in its model name._

Hewlett Packard: The HP 33s and HP 35s models, but no others.

Texas Instruments: All TI-30X and TI-36X models. Any Texas Instruments calculator must contain either TI-30X or TI-36X in its model name.

I've never used Casio or HP calculators - we always had TIs in school and they're what I've always used. My trusty TI-89 has been my sole calculator for years. The only one of the TI calcs on the list that I'd consider is the TI-30XS Multi View (yay for Pretty Print!). I think since it has TI-30X in the model name, I could use that one, at least according to NCEES.

I've read that the HP 33s is the "best" calculator on the allowed list, but I've never done the RPN thing. The spec sheet says it can be used in either RPN or algebraic mode, which helps. What's the fuss over the HP - is it because it can store equations and formulas?

I might grab one of each and see what I think - I know the HP is allowed and if I bring both of them in October, I'd be fine as long as I'm familiar with both.

Thoughts? Which one did you get, and why?


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## Road Guy (Feb 12, 2008)

I think most people (that I talk to) use the brand they have been using, it seems to have the most similarity. but you defin want to get it early &amp; get familiar with it.

I was an HP guy so I used the HP 33s, even though it was different than the 48, its was close enough...


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## Matt-NM (Feb 12, 2008)

I also used a TI-89 back in school and now at work. I decided to get the HP 33s for the PE in April, probably because of the programming capabilities (which I have yet to even look at). I would definately set it to algabraic mode if you are used to TI's. Regardless of which one you choose, get it soon and get familiar with it. Use it exclusively, even at work. It's probably a good idea to get two just in case one goes out during the exam.


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## Desert Engineer (Feb 12, 2008)

The brand/type of calculator is less important than your familiarity with it. One could pass the exam with a $5 Wal-Mart calculator (provided it was allowed), if they were familiar with it. Don’t get caught up in the calculator hype.


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## Katiebug (Feb 13, 2008)

I think the HP versus TI thing is generational. Those of us born in the 70s and 80s would have likely used TI calculators starting from elementary school, thanks to their near-monopoly in education. The younger engineers at work exclusively use TI graphing calculators (even if we don't need to graph all that often!). All of the older guys at work use HPs, many of them looking well-used, and they all use RPN for some reason. We never even learned RPN!

My father in law is a high school math teacher and is going to get me that TI for super cheap, and I'll pick up the HP, too. I like the idea of programming a few common equations into it, but I'm also the kind of person who'd want to check my equation anyways. The HP seems to have a nice equation solver, so we'll see which one I prefer...

Anyone choose the Casio? I'm just curious as to why people chose the calculator they did.


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## roadwreck (Feb 13, 2008)

Katiebug said:


> Anyone choose the Casio? I'm just curious as to why people chose the calculator they did.


I chose the Casio. I actually bought the Casio and a TI, and worked with both while studying. I figured I'd lean towards the TI since I had been using TI's since middle school, but to my surprise I found I preferred the Casio as my primary calculator and used the TI for a back up.

Like others have said, the most important thing is to get familiar with whichever calculator you are going to be using for the exam. Studying with a calculator that you won't be allowed to use on the exam is doing yourself a disservice.


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## jroyce (Feb 13, 2008)

I was an HP guy growing up and still use the HP TI-84 at work. I picked up an HP and tried to use it but it felt to me that everything was backwards on the HP. I found that the TI was easier to use because I was used to it and when I was studying the last thing on my mind was trying to figure out how to use the calculator.

I figured if I didn't know the material then the calculator wasn't going to help me anyway so I stuck with the one that I knew. Just my 2 cents though


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## roadwreck (Feb 13, 2008)

jroyce said:


> when I was studying the last thing on my mind was trying to figure out how to use the calculator.
> I figured if I didn't know the material then the calculator wasn't going to help me anyway so I stuck with the one that I knew. Just my 2 cents though


I had been using a couple TI graphing calculators for years, so switching back to a scientific (even one the same brand as my graphing calculators) was a little different. I would much rather be searching for the pi button when I'm studying rather then when I'm being timed on the actual exam. Plus I was able to find some of the more useful advanced features of the calculator (like the simultaneous equation solver) while I was studying which I never would have discovered otherwise.


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## Guest (Feb 13, 2008)

Katiebug said:


> I think the HP versus TI thing is generational. Those of us born in the 70s and 80s would have likely used TI calculators starting from elementary school, thanks to their near-monopoly in education. The younger engineers at work exclusively use TI graphing calculators (even if we don't need to graph all that often!). All of the older guys at work use HPs, many of them looking well-used, and they all use RPN for some reason. We never even learned RPN!


Hey ... are you calling me chronologically advanced?? A dinosaur even ??!!!! 

I was born in 1971, so I guess I am on the cusp of your generational divide. I started using RPN my first semester of college - never turned back. For my upper division work, most of the classwork/exams required one to KNOW and be able to program auto-lisp per the HP model of the day (48-GX had just become popular) in order to solve problems. RPN has been drilled into me that deeply.

Enter the P.E. exam. I tried really, really hard to use a T.I. It isn't that the T.I. didn't have the necessary functionality, it was that I just had a hard time in accurately entering calculations via algebraic entry. I found myself floundering and getting frustrated because of numerous miskeyed strokes. I promise you, this test is about timing - and if you are slow on the calculator you are giving up A LOT!

Cut to the chase - I purchased an HP-33S for my last exam. I credit the right calculator (in terms of comfort, not functionality) going a long way towards successfully passing this exam. After all, an engineer is only as good as the proficiency he holds with his tools.

Now on to YOUR point ...

I think you need to sum up what functionality and level of comfort that YOU need in a calculator. The EEs often talk about ease of converting from rectangular to polar and vice-versa seemlessly. I know Civils talk a lot about 'programming' algorithms for pipeflow and such but I would say that isn't necessary - I didn't have a single programmed equation in my calc and don't think it hurt me. :true: For me the finer points of functionality were: 1. RPN entry and 2. Multiple viewable stacks. Other than having the other typically scientific calc keys, the remainder was gravy.

I would start to work problems and see what you feel like you need for comfort and ease of problem solving.

JR


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## Capt Worley PE (Feb 13, 2008)

I've been using TI-30s since they had red LED indicators, so I went with the TI-30. However, when I took it in October, they only allowed the TI-30 X II S. On the II models, you don't input formulas the same way as the regular TI-30s and I absolutely hated that calculator. I had it enshrined with my PE certificate and NCEES pensil, since I knew I was never gonna use it again.


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## LionCE (Feb 13, 2008)

I used the HP33S for the simple fact that it wasn't RPN exclusively. I never learned RPN and didn't want to learn something new for the exam.

My forefathers would have been very upset since I am a Polander.


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## Jennifer Price (Feb 13, 2008)

I grew up on the TIs and used the TI85 - 89 in high school and in college. I loathed the HPs at the time. But when I started studying, my company at the time had bought all the engineers the HP and so I started using it (very reluctantly). Now...I love my HP and still use it for _everything_. I get frustrated trying to use a "normal" calculator (as my hubby calls everything but HPs) and will probably never go back to the TI.


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## jfusilloPE (Feb 13, 2008)

I went with the Casio fx-115MS (switching from a programmable TI-85).

I chose this model because when I went into Wally World, this happened to be the only model on the approved list that was available, and they even had more than one!

I agree with everyone else that it is not the calculator that you choose, but the time you spend with it. I have packed away my TI-85 and have been using my new shiny Casio since that time. It is really hard to go back and just pick up someone else's TI and start to do calculations on.


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## TXengrChickPE (Feb 13, 2008)

I also went with the Casio (I'm Civil/Structural). I used TI's all through high school and picked up a used HP-48GX during my sophomore year of college... I LOVED RPN!!! But, I borrowed someone's HP-33 once and HATED it. So, about six months before I was going to take the test I went through the list of allowed calculators and bought the cheapest one ($14.99 for the Casio). I figured if I didn't like it, I was only out $15, and if I did, I could afford to get a couple as backups. I used it exclusively for about a week, put my trusty old HP-48GX in it's soft case and haven't gotten it out since. I probably couldn't use RPN now if I tried... but the Casio does everything I need it to do.

I think it just comes down to knowing your calculator... at this point you don't have time to learn 3 or 4 calculators before April... pick one and run with it. Hide your old calculators and use the exam calculator for EVERYTHING. Then, before the exam, buy at least one more IDENTICAL calculator as a backup in case your batteries fail or your primary calculator falls on the floor and gets stepped on by a 350lb proctor... (hey, it could happen!)

The 2nd calculator must be identical to the first, or it's useless. Sometimes, even the same family of calculators will have different keypad layouts, which will cause you to lose time during the exam.


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## EL Nica PE (Feb 13, 2008)

I bought the HP 33s and Casio FX-115MS they're both great calculators. I suggest buying both b/c of the reason that you need a backup calulator just in case! The casio FX-115MS is only $14.99.


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## gymrat1279 PE (Feb 13, 2008)

I grew up using TIs and I used the TI-30X IIS on the PE in October 07. I used the same one on the FE when I took that as well. I think I took the first FE exam where they regulated what calculator you could use (April 04) so I was sort of familiar with it already. I liked that it had a 2-line display and the input was similar to my TI-89. I started using it the first day I started studying and I agree with everyone else, become familiar with whatever calculator you choose and you shouldn't have problems if you know the material. As far as being able to store equations, I don't think that is a necessity because you will have been studying so much by the time you take the exam, you will know most of the equations that you will use by that point. I would also suggest the back up calculator, but I would recommend having the same calculator for both your main calculator and a back up, not a TI for one and an HP for the other.


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## LionCE (Feb 13, 2008)

If I am not mistaken I bought the HP33 through www.business-supply.com. I compared prices and they had the best price. Check www.dealtime.com and they will compare the prices for you.


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## kevo_55 (Feb 13, 2008)

I got a TI-85 in high school and used it through college and my first job until I started studying for the exam.

For some reason, RPN really stuck on me and I decided to buy a HP33s.

I've actually never looked into programming it either!


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## IlPadrino (Feb 13, 2008)

The price of the 33S has dropped significantly ($20 on $60) since the 35S came out last year. I *hate* using a "normal" calculator because I can never remember all the parentheses needed. For me, stacks are a natural way to think, so I love them.

I don't think ANYONE should change from algebraic to RPN just for the PE exam...


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## Dark Knight (Feb 13, 2008)

If you are going to take the Power module of the EE test my best advice is to go with the Casio FX-115ES. It manages the complex numbers so easily that a caveman can...never mind. You got the idea.

FX-115ES should be the weapon of choice for the EE Power. I tried the HP-33s, did not work for me.


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## Brody (Feb 13, 2008)

I tested and worked with the Casio fx-115MS, the HP33s and the TI-36X Solar.

Since time is of the essence on the test, it is all about ease of use.

I preferred the Casio. For me the feel and response of the keyboard was very important in order to rapidly and reliably enter keystrokes. Of the three the Casio has the best feel to the keyboard; the keys are very easy to push. You don't have any time to spare so you don't want to be slowed down on your keystroke entry. It also has the best display in my opinion. I am still using it at work.

The HP 33s keys are laid out in a very user unfriendly chevron pattern and are stiff. The display is a murky green.

The TI-36X Solar comes out in the middle display and keystroke wise.

Don't worry about progammability because you will only be using the basic functions. Whichever one you use, become very familiar with it.


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## LionCE (Feb 13, 2008)

HP33S the display can be lightened and darkened, neat feature I thought.

A thing to think about if you are looking into a solar powered model. The room may not be conducive to the solar cells. I don't think I could have gotten away with using a solar powered model for the exam.


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## ufcfan (Feb 13, 2008)

fx-115ES...Easy to use, get the work done (I passed), and it costs less than $20.


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## C-Dog (Feb 13, 2008)

TI-30XIIS. 15.00 at staples - got 2. I have used TIs forever and thought there was no need to switch now.


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## mudpuppy (Feb 13, 2008)

I ruled out the HP immediately since I'm RPN illiterate. That narrowed it down to two: a TI and the Casio fx-115MS (I think only three calculators were allowed for the 4/07 exam). In reading reviews for the TI and Casio, it looked like the Casio was much easier to use for complex numbers. Since being able to work with complex numbers quickly is important for the EE exam, I went with the Casio.

Since I haven't used the HP or TI, I can't confirm what BIO says, but I can say that I'm very happy with the Casio, and it will replace my TI-85 when the 85 finally dies. I do have a coworker (also EE/Power) who tried both the TI and Casio for the exam and preferred the Casio as well .


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## Tark62 (Feb 15, 2008)

> I ruled out the HP immediately since I'm RPN illiterate.


The two currently approved HP calculator models, the HP-33S and HP-35S, can be set to operate in either RPN or conventional algebraic mode. In fact, this has been true of every HP calculator that has been introduced over the past several years. So it's worth considering these models even if you don't use RPN.

If you like to "customize" your calculator with specific functions, programs, or equations that you use often, then the HPs are the way to go, since they are the only NCEES-approved models with programming capability. I found this to be a time-saver on the exams, although it's just a convenience and not a necessity.


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## KEG (Feb 15, 2008)

I've always used TI calculators. The TI-68 was the best, especially for complex number calc's. However, I bought an HP 33 for the Oct. 07 exam. I used it for the test and have used it at work. Now I like it even though I was not fond of it to begin with. Whatever choice you make (TI, HP, or Casio), get comfortable with it and know how to use all functions. You don't have time to "figure out" the calculator during the exam. Just my 2 cents.


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## rudy (Feb 15, 2008)

I have always used non-RPN calculators, could never get used to the keystroke order. I started with the TI-60 in high school.

For my first attempt at the exam, I used the TI 30XA. I bought two of them. $15 each at Radio Shack.

For my second attempt, they changed the calculator list. A friend of mine lent me her Casio FX-115MS. I bought a Casio FX-115MS as a backup at Office Max for $15. It took a couple of weeks to get used to it because some of the keys were different. I liked it because it had a wide screen that fit two lines of entry, which displayed the numbers and operations (+, -, etc) you were entering. If I had my choice, I would stick to the TI, only because that is what I am used to.


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## RIP - VTEnviro (Feb 17, 2008)

I used the TI line of graphing calculators in college but it's overkill to use one of those for basic calculations around the office. I found myself using my trusty old Casio scientific calculator from high school. I bought the fx-115MS for the exam, and it operates nearly identically, with a few new bells and whistles you'd expect from a 10-year newer product.

I like it because you enter the commands as you would if you were writing in on paper, which is how I think.


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## jartgo (Feb 17, 2008)

Jen Evans said:


> I grew up on the TIs and used the TI85 - 89 in high school and in college. I loathed the HPs at the time. But when I started studying, my company at the time had bought all the engineers the HP and so I started using it (very reluctantly). Now...I love my HP and still use it for _everything_. I get frustrated trying to use a "normal" calculator (as my hubby calls everything but HPs) and will probably never go back to the TI.



I had a similar experience. I read about the calculator policy almost a year before I took the exam this past October. The only calculator I ever used was a TI-89 that I had bought in 1999 when I started college. I used this calculator through my entire college "career" and could use almost all of the functions on it. I loved the calculator and was pretty disturbed that they had gone to this "new" policy. At any rate, with some time before the exam, I opted to give the HP 33 a try. Initially I chose this calculator because it was advertised as having programming capability (a feature I used extensively in the TI89) and it could be used in algebraic mode (I was scared of RPN). After getting the HP33, it took me a couple of months to get used to (the keypad is very "busy" and still takes me a while to find what I'm looking for sometimes), then I decided to see what RPN was all about, took me another few months to get used to that. By the time I started studying for the PE exam (a few months in advance), the HP33 had become my calculator of choice and RPN was the only way to work. The RPN really is useful for multi-level equations, but it does take some time to realize the benefit. I didn't use the programming because by the time I started thinking about it, I didn't have time to figure it out....I found it to be completely different than the programming for the TI89 that I was proficient at. What I did find somewhat useful was the equation solver in the HP33. I now use the HP33 exclusively at work.

To cut a long story short, the April exam takers probably don't have any time to switch, but if you've got more than 6 months before the exam, I'd encourage you to start using the HP enough in advance that you already know how to use the calculator by the time you start studying. The HP is superior for it's solver, in my opinion. As others have stated, being comfortable with your calculator is more important than any special function.

this guy just cracks me up, so I'm going to include him here:

arty-smiley-048:


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## Sschell (Feb 17, 2008)

I have always been a ti guy (born in 79, so I fit katiebug's theory). Since the HP33s was the most expensive calculator allowed, and at the time I felt the need to compensate for my PE-ness deficiency... thats what I used.

I went as far as to learn RPN for the test and now use RPN almost exclusively... except when I need to use a good calculator and break out my old TI.


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## RIP - VTEnviro (Feb 18, 2008)

> this guy just cracks me up, so I'm going to include him here:


Next time, try this!


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## squishles10 (Feb 18, 2008)

^^ very helpful, thank you. ;-)

I used a TI all through school (also born in 79), and until this year when I was told how much faster RPN was, so for the exam I switched to the HP. It took me about a week to figure out, and I would always check my answers but it wasn't bad at all. I too, can't go back to "regular" calculators anymore and frankly don't know how I ever used them. I don't see a problem with changing calculators for the exam, I did. If you start now you'll be fine. I think the reason the HP is the "best" calculator is the advanced functions it has. If you see chapter 1 or so in the CERM, it explains how to do all that stuff with a basic calculator if you've forgotten (I always mess up exponents, so it's nice to have).

As my coworker said "Once you go PACK, you'll never go back." Haha, but true.


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## Brianne (Feb 18, 2008)

I bought a TI-36 for the test and now it's my favorite calculator. It can easily handle the switching between angles in decimal degrees and angles in DMS that is necessary for the CA Surveying test for the Civil PE.


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## Dleg (Feb 18, 2008)

I grew up as an RPN user. But I stashed my HP away in storage when I left the states, and forgot how to use it. I used the Casio fx115ES for the PE exam, and I think it's a fantastic calculator.

I recently purchased an HP 35s, though, and it's a really nice piece of equipment. Defintely wins the "cool" contest among the lsit of approved calculators (a geeky kind of cool, anyway). If I was studying for the PE exam, that's what I would choose to learn now, just because I would have the time to learn it, and RPN is faster and more intuitive, once you get used to it.

But I'm still using my Casio at work. Not having any exams to study for, there's no incentive for me to learn my cool new HP.


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## RIP - VTEnviro (Feb 19, 2008)

> RPN is faster and more intuitive, once you get used to it.


I can see faster, but how is it more intutive? I'm not arguing, just honestly asking. Take 2 + 2 = 4.

I just don't see how 2, 2, ENTER is more intuitive than 2, +, 2, =


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## roadwreck (Feb 19, 2008)

^^

I'm going to agree with VT here, if it were more intuitive then I shouldn't need to get used to it. I should just get it, right?


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## Capt Worley PE (Feb 19, 2008)

^Yup!


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## busbeepbeep (Feb 19, 2008)

I used the Casio 115MS, but now that the ES is allowed again, I'd recommend that one. (for EE-power)


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## Guest (Feb 19, 2008)

VTEnviro said:


> I can see faster, but how is it more intutive? I'm not arguing, just honestly asking. Take 2 + 2 = 4.
> I just don't see how 2, 2, ENTER is more intuitive than 2, +, 2, =






roadwreck said:


> ^^I'm going to agree with VT here, if it were more intuitive then I shouldn't need to get used to it. I should just get it, right?


Don't be hatin' because you guys are RPN-challenged!! 

JR


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## Tark62 (Feb 19, 2008)

> I can see faster, but how is it more intutive? I'm not arguing, just honestly asking. Take 2 + 2 = 4.
> I just don't see how 2, 2, ENTER is more intuitive than 2, +, 2, =


How did you add two numbers in elementary school? Probably like this:

(1) You wrote down the first number on a piece of scratch paper;

(2) You wrote down the second number underneath the first number;

(3) You performed the addition

An HP-33S or HP-35S calculator works in exactly the same way, like you were using scratch paper:

(1) You input the first value, followed by ENTER, which raises the first value to the upper line of the display;

(2) You input the second value, which goes underneath on the lower line;

(3) You press + to perform the addition.

If you've ever solved math problems with scratch paper, then you should be able to "get" RPN. It's just virtual scratch paper.

Ultimately, the preference for RPN vs. algebraic comes down to a "philosophical" difference in problem solving, which becomes more pronounced as equations become more complex. Suppose you have a large complicated equation -- would you rather solve it as one big problem, or as a series of small problems?

Modern algebraic calculators are optimized for the "one big problem" approach. They allow the user to input very complex equations, which can be formatted exactly as they would be in a textbook. This approach will work, as long as you've copied the equation perfectly. However, some people feel that this approach encourages copying rather than thinking, and that it may lead to undetected errors if the equation has not been copied or understood perfectly.

RPN calculators, in contrast, are optimized for the "series of small problems" approach. RPN does not allow pending operations or expressions in parentheses: the user is forced to think through the equation one step at a time (as with scratch paper), and sees all intermediate results (as with scratch paper). Some people are more comfortable solving complex problems this way, as opposed to doing it in one big step.


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## Sschell (Feb 19, 2008)

^yeah... take that!


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## Dleg (Feb 19, 2008)

_ZZZZING!_


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## mudpuppy (Feb 19, 2008)

There's nothing that says you _have_ to do problems in one big step with an algebraic calculator. I do calculations of the following form quite often in my work:

46^2/(1.5*40*cos(75-arccos(.9))

However, I don't enter it this way in my calculator. I do this: 46^2/1.5/40/cos(75-arccos .9 =

To me this is perfectly logical and I can type it in quickly, whereas I wouldn't know where to start with RPN.


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## Katiebug (Feb 19, 2008)

I decided to get the HP 33s, and my father in law (a math teacher) is getting me one of the TI calculators on the list for free, so I can try out both. I do love TIs, but I like the idea of an equation solver like the HP has.


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## Dleg (Feb 19, 2008)

The 115ES also has a solver function. Not sure if the HP works better, though. The few times I tried the solver function on the 115, it chugged away for literally several minutes, and once did not even have a solution (an engineering economics problem of a variety you are NOT likely to ever see on the PE exam). But it generally worked for solving Manning's equation for diameter or depth of flow, although I genuinely believe that just back-plugging the four possible answers (on a multiple choice question) into the equation is faster. And safer - at least then you know what you are doing.


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## Tark62 (Feb 19, 2008)

> There's nothing that says you have to do problems in one big step with an algebraic calculator.


No, of course not. But if you like to solve problems in step-by-step mode, then RPN calcs can do it more efficiently and (for most people) more easily. They are designed to work that way, and algebraic calcs aren't.

Your "perfectly logical" example demonstrates this point. For example, it isn't actually step by step: it looks like the final "cos 75-arccos .9" expression contains multiple pending operations, which are evaluated "all at once" with the final press of the = key. The reason for doing it this way is presumably to avoid using closing parentheses. The example also includes some rather significant alterations to the original equation: two multiplications were changed to divisions, again presumably to avoid the use of parentheses.

It appears that you are prepared to go to some lengths to avoid parentheses and pending operations (although you were not totally successful in this case). If that's the way you like to calculate, then maybe you should give RPN a try. The same expression can be solved with RPN without changing any of the operations, without the need for any parentheses, while showing every intermediate result, and using the same number of keystrokes.


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## Tark62 (Feb 19, 2008)

> The 115ES also has a solver function. Not sure if the HP works better, though.


My impression is that the Casio and the HPs all have decent equation solvers. The HPs have the advantage, though, because you can store commonly used equations (e.g. time value of money, Manning's equation) and recall them, rather than re-entering them every time. This capability is the basis for the "33S Essential Equations" books published by the other board.

Whether this feature is really helpful on exams is another issue, because most of the equations on NCEES exams are simply not that complex. I do think that economics problems can be solved faster if you have a calc with a pre-programmed time value of money equation, rather than using the lookup tables in the FE handbook.


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## EM_PS (Feb 19, 2008)

The casios are my choice for alot of the same things Brody already said. The HPs are the most robust (most $$ too), and are programmable. But do you really want to scroll thru a single letter defined set of program names, versus just working with what you know, and using the casio in the SOLV mode, maybe even back solving for the answers given as Dleg mentioned. In addition to this board, check out the reviews of the various calcs on Amazon. seriously, the reviews on the HP-33 totally scared me away from it.

I understand RPN, just don't understand why people are so fanatical about it. Its like for the fans of it, you all are so passionate(!) about it - but for ones who don't care for it, no biggie, just do the algebraic thing.

I use alot of Excel, and mathcad, and matlab, and even visual basic - and no virginia, none of those venerable software platforms remotely have any logic approaching the RPN lmethod of problem solving. I like my method of problem solving to be fluid, whether punching a calc, or writing code in MatLab.


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## Katiebug (Feb 19, 2008)

Tark62 said:


> My impression is that the Casio and the HPs all have decent equation solvers. The HPs have the advantage, though, because you can store commonly used equations (e.g. time value of money, Manning's equation) and recall them, rather than re-entering them every time. This capability is the basis for the "33S Essential Equations" books published by the other board.
> Whether this feature is really helpful on exams is another issue, because most of the equations on NCEES exams are simply not that complex. I do think that economics problems can be solved faster if you have a calc with a pre-programmed time value of money equation, rather than using the lookup tables in the FE handbook.


The economics equations are going to be programmed in. Despite having a master's degree in management, I can't remember those formulas to save my life! There are a few others that I think will be helpful, too.

I don't use the equation solver all that often on my TI-89, but when I do use it, I like it. The TI calculators allowed by NCEES at the moment don't have a solver, at least not one that I've seen referenced in the specifications.

Yeah, the FIL can get me any TI calculator for free, so I'm just going to try both and see which I feel more comfortable with. I have the feeling the HP is going to stay in algebraic mode...RPN just doesn't make sense, although maybe it will if I try it.


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## Dleg (Feb 19, 2008)

Well, having used both RPN and regular (for the PE exam, too), I can say with some authority that neither mode is "superior". They both work well. I recall liking RPN better after becoming proficient at it. But I was very impressed with the capabilities of my Casio 115ES by the time I learned its deepest workings, like the statistical operations.

But look at it this way: Studying for one of these exams is perhaps the perfect, and perhaps only opportunity you are ever going to have to really "learn" a new calculator, so why not go for RPN? It's the ultimate badge of engineering prowess (I was going to say geekiness, but thought better of it).

But please, if you're going to take a stab at RPN, just go for the new HP 35s, and not that piece of crap 33s.

(I've never used a 33s so I have no idea what I am talking about in that regard! But the 35 is very nice. Even comes with a DVD about the history of HP calculators. )

Don't forget that whole programmability thing - it makes the HP more versatile after the exam (of course I haven't used it yet, in a year and a half now).


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## RIP - VTEnviro (Feb 20, 2008)

> If you've ever solved math problems with scratch paper, then you should be able to "get" RPN. It's just virtual scratch paper.
> Ultimately, the preference for RPN vs. algebraic comes down to a "philosophical" difference in problem solving, which becomes more pronounced as equations become more complex. Suppose you have a large complicated equation -- would you rather solve it as one big problem, or as a series of small problems?


OK, I get that response. That makes sense.

I philosophically like to write out the whole equation on paper before I attack the calc.

And you can do a large complex problem in algebraic notation. Most calculators these days store the previous answer or two and you can do the calc in steps.

I often do that rather than input a giant equation for the exact reason of avoiding an input error.

More than 1 way to skin a cat I suppose!


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## TXengrChickPE (Feb 20, 2008)

Tark62 said:


> How did you add two numbers in elementary school? Probably like this:
> (1) You wrote down the first number on a piece of scratch paper;
> 
> (2) You wrote down the second number underneath the first number;
> ...


I dunno... maybe I'm weird (well, I KNOW that I'm a little strange sometimes) but when I added 2 numbers in elementary school, I did it like this:

1) Write first number

2) Write a + sign below and to the left of the first number

3) Write second number next to the + sign

4) Underline the bottom line

5) Perform the addition

Which correlates exactly to how I enter the information on my algebraic calculator:

1) Key in first number

2) Press + sign

3) Key in second number

4) Press = button

5) Calculator performs the addition

Don't get me wrong, I did use RPN for several years and liked it... I just don't agree that it is "intuitive" in any sense of the word!


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## RIP - VTEnviro (Feb 20, 2008)

^ I agree with TX 100%!

I think the reason I'm such a big Casio fan is because of the 'just like on paper' method of inputting the arguments.


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## ODB_PE (Feb 20, 2008)

Dleg said:


> Even comes with a DVD about the history of HP calculators.


Is it lame to want to watch that DVD? Netflix doesn't have it yet. What to do (except for buy the 35s?)

Added - HP has about an 8 minute video online - the same thing?


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## Capt Worley PE (Feb 20, 2008)

ODB_PE said:


> Is it lame to want to watch that DVD?


I'm in trouble if it is.


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## Guest (Feb 20, 2008)

Oh boy .. I can see this thread is heading for the Hall of Fame!

Argument is going to dwindle to ...

Tastes Great !!

........................... Less Filling !!!

:bananalama:

JR


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## RIP - VTEnviro (Feb 20, 2008)

I was always a less filling guy.


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## maryannette (Feb 20, 2008)

TASTES GREAT!!


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## Tark62 (Feb 20, 2008)

> when I added 2 numbers in elementary school, I did it like this:
> 1) Write first number
> 
> 2) Write a + sign below and to the left of the first number
> ...


Admittedly, that way will work, but it turns out that Step 2 is completely unnecessary. You can skip it and save a step, while still adding the numbers correctly. Try it on a piece of scratch paper and you'll see !


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## Tark62 (Feb 20, 2008)

> Argument is going to dwindle to ...
> Tastes Great !!
> 
> ........................... Less Filling !!!


Obviously both RPN and algebraic calculators work, and can be used to pass NCEES exams. So yes, it is a matter of personal taste. For exam purposes, the most important thing is to be thoroughly familiar and comfortable with your calculator, regardless of model.

A simple way to see if you are a "tastes great" person or a "less filling" person is to consider a problem like this one, which includes three operations:

(36 + 77) * (5.34 - 4.66)

If you see an addition, then a multiplication, and finally a subtraction, then you are an algebraic person.

If instead, you see an addition, then a subtraction, and finally a multiplication, then you are an RPN person.


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## maryannette (Feb 20, 2008)

Good point, Tark, but do you really think that can be the end of the debate?


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## Tark62 (Feb 20, 2008)

> Good point, Tark, but do you really think that can be the end of the debate?


Yes. That was the definitive final word.


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## maryannette (Feb 20, 2008)

There is NEVER a definitive final word here.


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## Dark Knight (Feb 20, 2008)

Are we or are we not engineers?

This has a simple solution: *Use the calculator that fits your needs and skills better.*

I am darn sure that the calc that JR used was not probably the best one for me and viceversa. He needed to perform some functions and I needed to do different things. I cannot say about Civil, Mech, and Chem Engs but I needed to do polar/rectangular math operations. Based on my experience the HP33 was not good enough. The Casio FX115ES worked out for me.

I am sure that the HP33 is a darn good calculator and it is probably better for other engineering branches and maybe for some EEs too. For my specifics needs the Casio was the one.

Bottom line, and repeating what I said at the beginning: *Use the calculator that fits your needs and skills better.*

If you feel better using an abacus be sure it is on the NCEES approved list.


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## maryannette (Feb 20, 2008)

There is NEVER a definitive final word here ... BECAUSE we are engineers.


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## Dark Knight (Feb 20, 2008)

maryannette said:


> There is NEVER a definitive final word here ... BECAUSE we are engineers.


 My bad then :15:


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## RIP - VTEnviro (Feb 20, 2008)

Tark62 said:


> (36 + 77) * (5.34 - 4.66)
> If you see an addition, then a multiplication, and finally a subtraction, then you are an algebraic person.
> 
> If instead, you see an addition, then a subtraction, and finally a multiplication, then you are an RPN person.


I see an order of operations problem. I'd add and subtract what's in the parentheses, then multiply, then get a beer. I don't think that makes me an RPN guy though.

LESS FILLING!


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## maryannette (Feb 20, 2008)

VTEnviro said:


> ... then get a beer. I don't think that makes me an RPN guy though.


I support every engineer's right to select their own means of solving problems, but does it have to be beer? What about a shot of tequila?


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## Capt Worley PE (Feb 20, 2008)

Never tequila.

Never.


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## maryannette (Feb 20, 2008)

Captain Worley PE said:


> Never tequila.
> Never.


I have some very good tequila memories.


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## Dark Knight (Feb 20, 2008)

maryannette said:


> I have some very good tequila memories.


In the 1-10 scale...how good?


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## maryannette (Feb 20, 2008)

BringItOn said:


> In the 1-10 scale...how good?


 :laugh: :blush:


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## Capt Worley PE (Feb 20, 2008)

If you can remember them, it wasn't tequila....


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## maryannette (Feb 20, 2008)

Captain Worley PE said:


> If you can remember them, it wasn't tequila....


Prior to loss of memory and/or puking, there is a very happy place.

I also have some non-memories resulting from tequila, but they were not as enjoyable, so I learned not to overindulge.


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## Sschell (Feb 20, 2008)

Tark62 said:


> Yes. That was the definitive final word.


I like this Tark character...

TASTE GREAT... is obviously more important. and RPN is better.


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## Dleg (Feb 20, 2008)

Actually, my Casio doesn't taste like anything. My HP 35s has a slight, grape-like flavor though.


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## Sschell (Feb 20, 2008)

Dleg said:


> Actually, my Casio doesn't taste like anything. My HP 35s has a slight, grape-like flavor though.


grape huh?

interesting, I have two HP33's, one has no smell the other distinctly smells like marijua...

nevermind.


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## Dleg (Feb 20, 2008)

ODB_PE said:


> Is it lame to want to watch that DVD? Netflix doesn't have it yet. What to do (except for buy the 35s?)
> Added - HP has about an 8 minute video online - the same thing?


That's probably the same thing. It was short, and not the greatest quality. I expected more. Much more.

When I bought it, actually, I had read a review (must have been pre-purchase speculation) that the DVD was a compilation of tribute videos submitted by fans as part of a Youtube contest. THAT would have been cool. Imagine my disappointment....


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## Guest (Feb 20, 2008)

Tark62 said:


> A simple way to see if you are a "tastes great" person or a "less filling" person is to consider a problem like this one, which includes three operations:
> (36 + 77) * (5.34 - 4.66)
> 
> If you see an addition, then a multiplication, and finally a subtraction, then you are an algebraic person.
> ...


The simplicity of your problem may lead to an incorrect assumption of how RPN would differ from algebraic entry, much like teaching someone multiplication and asking them to multiply by zero or one - do they really understand the nuances of the mathematical operator?

A more involved example is in order ....

Consider the following:

This problem will challenge you to think either algebraically or by RPN! 



VTEnviro said:


> I see an order of operations problem. I'd add and subtract what's in the parentheses, then multiply, then get a beer. I don't think that makes me an RPN guy though.


To an extent, that is true VTE; however, it isn't the entire gist of the approach.

When I was taking calculus, my professor taught me to start solving problems from the MIDDLE (e.g. inside parathesis or complicated operands like trig functions). This is how RPN works - break down the problems piecemeal to form simpler expressions. That's why there are multiple stacks - one stack per simplified expression.

That way of thinking has become so pervasive for me that even my spreadsheet calculations have multiple columns that functionally serve as 'stacks' so that I may easily pick up on arithmetic errors within my calculations.

Just my :2cents: to add fuel to this argument.

JR


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## Tark62 (Feb 20, 2008)

> When I was taking calculus, my professor taught me to start solving problems from the MIDDLE (e.g. inside parathesis or complicated operands like trig functions). This is how RPN works - break down the problems piecemeal to form simpler expressions.


In fairness, you can use the same general approach with an algebraic calculator. You can use an algebraic calc to break down problems into simpler expressions, store intermediate results, and then combine those intermediate results to get the final answer. People do it all the time.

But if you do calculations this way, then the RPN calc has a big edge in terms of ease and efficiency. The fundamental difference is that an algebraic calc puts operators between two numerical arguments, e.g. 2 + 3. This approach works fine for some problems, but is not optimal if you need to work with a series of saved intermediate results. If you want to add the last two saved results, for example, you have to "juggle" them in some manner to get the + operator between them. Algebraic calcs provide ways to do this, but they are clumsy.

The RPN calc, in contrast, puts the operator after the two numerical arguments, e.g. 2 3 +. This approach happens to work very nicely with a series of stored intermediate results. If you want to add the last two intermediate results, for example, you just hit the + key. No juggling is required, because the last two intermediate results are already in place and waiting for the operator.


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## EM_PS (Feb 20, 2008)

BringItOn said:


> Bottom line, and repeating what I said at the beginning: *Use the calculator that fits your needs and skills better.*
> If you feel better using an abacus be sure it is on the NCEES approved list.


:deadhorse: Do they make RPN abacuses?

My fluid mechanics prof challenged the students, using an oversized teaching prop slide-rule, as to whether we could beat him using calculators in a series of calcs. It wasn't close. . . maybe the 'girth' of the slide-rule was too much(!) - he was of wirey build. . .he put up a pretty good fight for maybe 1.5 secs


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## Tark62 (Feb 20, 2008)

error_matrix said:


> My fluid mechanics prof challenged the students, using an oversized teaching prop slide-rule, as to whether we could beat him using calculators in a series of calcs. It wasn't close. . . maybe the 'girth' of the slide-rule was too much(!) - he was of wirey build. . .he put up a pretty good fight for maybe 1.5 secs


Skilled abacus operators are supposed to be quite competitive with calculator users when it comes to four-function arithmetic -- most of the time needed for the calculation is for numerical input, and someone who knows what they are doing can slide the counters on the abacus rods faster than you move your finger around a calculator keyboard. However, it takes a lot more practice to become proficient with the abacus.

I have an old slide rule, and learned how to use it, but am much, much slower than with the calculator. I use it sometimes anyway though, just because I find it so amazing that complex equations -- with trig functions, logs, roots, and exponents -- can be solved accurately with the use of three bamboo sticks.


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## IlPadrino (Feb 21, 2008)

It's the Stack, Stupid. The bigger the stack, the better...

My nine-year-old wants to start using a calculator to do some math work. I told him no problem so long as he could learn to use RPN. He's getting the hang of it, though. I think I'll need to hide the batteries soon.


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## Desert Engineer (Feb 21, 2008)

I had thought about taking an abacus into the PE exam to see if they would bust me for having a non-approved calculator. a kind of ironic protest to the backwards calculator rules.


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## wilheldp_PE (Oct 5, 2009)




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## EM_PS (Oct 5, 2009)

I'm kinda pissed. . .my backup calculator (Casio Fx115-ms) is gone! I lent it to stepdaughter last semester &amp; she somehow managed to return it to me in the form of a TI-36x! absolute junk!

might be taking this October's exam w/ my fx115-ES going solo


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## csb (Oct 8, 2009)

I brought four calculators the last time- two Casios and two TI-36x. I had bought two POS TI's before I saw the light and went with the Casio. Overkill? Yes. Calm my nerves? Yes.


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## EM_PS (Oct 8, 2009)

^ wanna express mail me one of your casios?

kidding, i think i'll go it w/ the 1 casio &amp; the TI running wing man. . .course a license hangs in the balance with this one. . .


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## Flyer_PE (Oct 8, 2009)

^ I viewed the money spent on the second identical calculator as cheap insurance. When you factor in a 6 month wait to take the exam again, even the HP doesn't seem like a large expense. I had a second HP 33 when I took the test. I sold it the week after I took the exam.


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## RIP - VTEnviro (Oct 13, 2009)

I too spent an extra $20 on an identical, backup Casio.

I have one at home and one at work now.


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