For some engineers, the choice of calculator can be a deeply personal one. For others, just a tool. And for some other engineers a source of analysis-paralysis.
If engineers were more like Jedi, we would construct our calculators as Jedi construct their lightsabers. Some engineers could do just that but the exam invigilators probably wouldn’t allow it.
If you are assigned technical examinations, you will need a non-programmable calculator.
So which calculator should you use? Which calculators fall within the rules and which do not? What are the more important features of a calculator for technical exams? This article will try to address these questions.
The FE Exam Calculators
If you might write the FE exam now or in the future, you might want to pick an NCEES approved calculator to also use on your technical exams.
The current list of NCEES approved calculators is as follows:
- Casio fx-115 and fx-991 series models
- Hewlett Packard HP 33s and HP 35s
- Texas Instruments TI-30X and TI-36X models
We’ll come back to this list throughout our discussion.
Non-Programmable Calculator Options
The National Technical Examinations Program “Exam Format and List of Aids” simply states “any approved Casio or Sharp model”. This appears to be a legacy thing – it is what the exams have said for decades. In some years the list will say “…any non-programmable Sharp or Casio is an approved model” or “Any non-communicating, and non-programmable calculator is permitted. (Casio or Sharp models are more common [LOL, in the 1980s!])“. The regulators lost an understanding that their calculator policy was taken from the University of Toronto Engineering calculator policy. The regulators became so bureaucratically confused that in 2023 they outlawed programmable calculators for the exams. So now CEAB students are allowed programable calculators for subjects that absolutely require them like MEC-B10 whereas non-CEAB applicants working every day in industry must write the same syllabus with one hand tied behind their back.
I wrote to PEO to ask specifically if the TI-36X Pro was allowed and they responded “As long as the calculator is non-programmable it is allowed into the exam…”. Good to know.
Casio fx-115ESPLS2 / 991-ES Plus C 2nd Edition
Best non-programmable calculator currently available at a low price. Highly capable.
Confusingly, Casio markets the same calculator under two model names depending on the country you live and both can be found available for sale in Canada. The “Plus 2nd Edition” has same processor and functionality as the previous “Plus” and changes are mainly cosmetic. If you have the older fx-115/991-ES then upgrading to the “Plus” or “Plus 2” will add some valuable functions. The hard cover contains 2 digit codes that you need to enter for scientific constants and unit conversions. This is more convenient than one might think versus scrolling through a menu.
Pros
- most popular non-programmable calculator in class
- low cost and readily available – buy one for the office, car and at home
- keystroke optimized – very fast & easy to use
- comes with excellent manual – short learning curve
Cons
- none – it remains the standard by which other non-programmable calculators should be measured
Casio 991-EX Classwiz
Highly powerful but discontinued. Not worth the price unless you need 4x4 matrices.
The EX was a new build calculator by Casio with very few changes from the Plus in layout and functionality. Unfortunately, Casio seems to have given up on this calculator model just a couple years after release. It has become very expensive to get if you can get it at all.
The biggest difference is perhaps the processor which speeds solve functions by over 5x from the Plus. The processor maybe will save you a few seconds on your exams. Processor speed is not a big need in a non-programmable calculator. They also replace the “LOG BASE-N” key on the “Plus” with an “X” key on the 991-EX. On the “Plus” you always have to press “ALPHA” + “X” and given “X” is used a lot and base-n logs rarely, this change on the 991-EX is an improvement. The display is more modern on the 991-EX but text is also smaller so that change is not so significant. The 991-EX also moves scientific constants and unit conversions to menus rather than the placard on the cover. Finally, you also can do 4×4 matrices. As soon as you need 4×4 you need 6×6 and beyond. But given the regulators have decided to no longer allow programmable calculators, if you can make use of 4×4, then you need it. At the same time, some useful number functions (LCD, GCD) from the Plus are dropped from the EX. The EX does have a spreadsheet mode but it seems at least to me superfluous on a non-programmable calculator when you can use the table mode.
Pros
- has some feature improvements over the “Plus”
- comes with excellent manual – short learning curve
- way faster processor than competition
- spreadsheet mode
- 4×4 matrices
- additional functions
Cons
- discontinued
- expensive if you can get it
- missing some lesser used functions from the “Plus”
Texas Instruments TI-30X IIS
The TI-30X is a very low cost calculator that is also on the NCEES approved list. However, it has far few functions than the other calculators covered here and just is not a suitable choice for the FE or technical examinations. It is a glorified “four banger” with some scientific functions and a good choice for quick sanity checks at the office or your kids’ geometry class. Take it to the beach. But please pick up a better calculator for your exams!
Pros
- very low cost
Cons
- not up to the job
Texas Instruments TI-36X Pro
The TI-36X Pro was in every way the TI answer to the Casio fx-115ES/fx-991ES. It has all you could want in terms of aesthetics and usability. Where it falls down is with keystrokes where it consistently requires more keystrokes than the Casio calculators (except the new fx991-CW). For example, to get to the fifth memory storage location takes five keystrokes.
Basically the TI-36X Pro is nearly as good but not quite as good as the Casio fx-115ESPLS2. Even the processor is an eyelid blink slower.
If your other calculator is a TI, you really can’t go wrong with the TI-36X Pro as they have a common layout & feel. But do make sure you get the “Pro” model as there are versions like the TI-36 “Solar” which have way less functionality.
Pros
- layout and functionality familiar to TI programmable graphing calculator users
- does everything you need to do with a non-programmable calculator
Cons
- more keystrokes than Casio fx-991ES/fx-115ES
- processor speed (low performance)
- high cost for what you get
Casio fx-991 CW Classwiz
The fx-991CW is in essence the fx-991EX with a menu driven interface like the TI-36X Pro.
The fx-991CW is the apparent replacement for the fx-991EX. It seems apparent that Casio wanted a calculator with with lots of capability but a simpler menu driven interface like the TI-36X Pro. As someone writing technical exams, you should be a power user of your calculator. This menu interface leads to added keystrokes that slow your work. For those who have used Casio calculators in the past, the fx-991CW is really an infuriating disappointment. But you can understand why Casio wants to market calculators to high school students, not engineers.
Pros
- All the power and functionality of the fx-991 EX it replaces
- good price
- does everything you need to do with a non-programmable calculator
Cons
- more keystrokes than Casio fx-991ES/fx-115ES
Sharp EL-W516TBSL
Did you notice that no Sharp calculator is in the NCEES approved list?
Despite the snub, the EL-W516T series calculators are very capable and feature packed.
A lot of comments online about accuracy issues with these calculators. Generally in engineering, three significant figures is enough and this calculator gets you at least “slide rule” close to that – so I don’t see it as a real problem for the end user. I assume the lowered accuracy has everything to do with compensating for a very slow processor. When compared with the 991-EX, the time to solve can be 3x – 30x as long. But again solving speed is not that important in a non-programmable calculator.
Pros
- lots of functions
- up to the job
Cons
- cannot be used on FE exam
- slow
- reduced accuracy on solving functions
- poor value for price
Final Verdict
A summary of the non-programmable calculators we’ve reviewed and the key features is shown below.
| Calculator | Functions | NCEES | Spreadsheet | Matrix | Table | Variables |
|---|---|---|---|---|---|---|
| Casio fx-115ES/991-ES Plus | 460 | y | n | 3×3 | y | 9 |
| Casio fx-991 EX | 552 | y | y | 4×4 | y | 9 |
| Casio fx-991 CW | 552 | y | y | 4×4 | y | 9 |
| TI 30x IIs | 27 | y | n | none | n | 5 |
| TI 36x Pro | 500 | y | n | 3×3 | y | 8 |
| Sharp EL-W516TBSL | 640 | n | n | 4×4 | y | 8 |
Verdict: The Casio fx-991ES Plus remains the best value.
But you can’t go wrong with any of these non-programmable calculators except the TI 30x IIs which is not up to the job.
It is far more important you read the manual, learn how to use every function, and practice than have the most powerful calculator. In a light saber duel, nobody is going to predict the outcome based on the design of the switch guard on the lightsabers.
