The TI-36X Pro is hands down the best calculator for the Electrical Power PE Exam and the good news is that it is CHEAP!
Let’s face it:
You are going to have a hard time solving complex math problems without a good calculator in your arsenal which is why we reviewed six different calculators from the NCEES approved list and picked the very best one.
The criteria to select the best calculator out of the six took into account the following:
- Is it on the approved NCEES list?
- Can it convert between polar and rectangular?
- Can it calculate polar numbers and rectangular numbers automatically?
- Can it add/subtract polar numbers from rectangular?
- Can it multiply/divide polar numbers from rectangular?
- (If it can’t, you will need to convert all numbers to rectangular or polar first)
- Is it intuitive and easy to use or is there a learning curve?
- How much does it cost?
To me, the most important feature of your calculator is making sure it can use polar and rectangular numbers together when carrying out any type of arithmetic.
If it can’t, then you are using precious minutes on the exam clock to first convert all of your vectors to either polar or rectangular each and every time you need to multiply, divide, add, or subtract.
Some problems require a mix of addition/subtraction (rectangular) and multiplication/division (polar) which means in some instances you will have to do this more than once.
This introduces additional unnecessary steps to solve questions during the pe exam which means increasing the chances of getting a wrong answer due to a slip in polarity, a simple math mistake, writing down the wrong number, or interpreting your handwriting wrong.
Don’t laugh, it happens to the best of us.
Let’s look at an example.
Say you had to solve for current I below
given the complex values for V1, V2, I2, and Z:
Where:
To solve for I, you would set up the following equation:
Using a calculator that can’t use both polar and rectangular at the same time (most can’t), you would have to manually convert your values SEVEN TIMES before getting the right answer since current and voltage are expressed in polar and impedance is expressed in rectangular.
Let’s count each time you would need to convert:
- To subtract the difference of V1 and V2 you would have to convert them both to rectangular
- Once for V1 and once for V2
- Then, since they are about to be divided by Z, you would have to convert the difference BACK to polar
- To divide by Z you would have to convert Z to polar
- To add this value to I2 you would have to convert it to rectangular
- Then convert I2 to rectangular before finding the sum
- Last, to get the answer for I, you would have to convert this value to polar since it is currently in rectangular from adding.
That is SEVEN unnecessary chances for something to go wrong under the stress of taking the PE exam.
Taking into consideration how many questions on the exam you would have to do this for would result in madness and a very high chance of getting a lot of questions wrong that you deserve the right answer for.
Luckily all of this can be avoided for just about $20 by purchasing the right calculator.
Let’s look at how quickly we could solve the above question using a calculator that can handle arithmetic equations such as addition, subtraction, multiplication, and division using a mix of both polar and rectangular numbers:
- Check and make sure the calculator is in polar mode since we want our final answer for I expressed in magnitude and angle
- Enter the following equation and press enter:
That’s it!
Pressing enter will give you the final answer for I in polar form like this:
How great is that?
Have I convinced you yet why this is so important and time saving?
Good!
Make sure you get a calculator that can do this and save time on the exam while cutting down on wasted time converting back and forth during study sessions.
TI vs Casio
Next, there are two main brands that have inexpensive calculators that can do this for you: Texas Instruments and Casio.
Specifically:
- The Texas Instruments TI-36X Pro calculator
- and the Casio fx-115ES Plus calculator
I favor Texas Instrument (TI) calculators.
Growing up in the American school system they were almost always the default brand used making TI calculators much more intuitive to use and less of a learning curve compared to Casio models.
Casio brand calculators, in my opinion, just feel strange and a bit foreign.
Kind of like being used to an iPhone and all of a sudden being given an Andriod, or being used to an Android your whole life and then given an iPhone with no warning.
However, some people swear by it. I have both and I don’t.
The good news is that you can get either for just about 20 bucks on A
mazon so it is pretty risk-free if you want to grab both and try them out like I did to see what works best for you.
Amazon sells them at a cheaper price than I have seen in stores and will deliver to your doorstep in two days for FREE if you already have a prime account (you can get a six-month free trial if you still have your .edu email address from college).
To purchase either the Texas Instruments TI-36X Pro or the Casio fx-115ES Plus calculator you can use either of the two links below.
Full disclosure: both of these are affiliate links that help to contribute a very small amount to cover the cost of this website.
To purchase the Texas Instruments TI-36X Pro Scientific Calculator
To purchase the Casio fx-115ES Plus:
Honorable Mention: The HP-35S
Make sure you have any ad block program turned off to view the Amazon widgets above that show the updated pricing.
Regardless of which calculator you choose, I recommend taking two to the PE exam.
This is going to sound silly, but what happens if you only have one calculator and it either:
- Runs out of batteries
- Gets a drink spilled on it
- Decides to stop working for no apparent reason
Is it unlikely that you will have trouble with your calculator during the exam?
Probably.
But consider how silly you would feel if after all of your hard work and financial investment to take the PE exam you end up with a dud of a calculator after the exam starts all because you didn’t take a $20 back up.
Now if you already have an approved calculator but it can’t handle polar and complex numbers together like we described above, then that is a perfect candidate to take as your back up.
Or go ahead and just bring two of the same, it’s really up to you.
Whatever route you decide to take, don’t forget to put fresh batteries in both a few days leading up to the exam.
Consider it cheap insurance.
To check and see if your calculator is on the approved NCEES list, visit the official NCEES calculator page:
I grew up using nothing but TI, but I started using the HP-35S for my PE problems and fell in love with how easy you can input mixed (rect./polar) formats into it. I’m looking at Amazon’s view of the TI-36X and it doesn’t appear to have a button for entering an angle, like in the casio or hp calculators.
Great article, thank you!
Moises, Thanks for the comment.
I will add the HP-35S as an honorable mention in this article in case other examinees like yourself find it more to their liking than the TI or Casio models already discussed.
For anyone reading this that does use the TI-36X Pro, and to answer your question directly, to enter a polar number with magnitude and angle on the TI-36X Pro:
1. Press second, complex (same button as Pi)
2. Press enter on choice 1: “<"
Enter the magnitude first, then use the steps above to add the angle afterward.
Example: 120V<30°
1. Type in 120
2. Press second, complex
3. Press enter
4. Type in 30
And that's it. You can use the polar number just like any other number in your calculator and it will automatically carry out complex vector mathematics for you.
I switched from Casio FX115 ES plus to TI 36x Pro calculator after reviewing this article. The TI really speeds up the calculations without converting back and forth between the polar and rectangular forms. Thank you Zach.
More power to the Casio guys (and girls) – but glad I got another one to see the light and join the dark side with the Ti!
Thanks for this tip/article Zach!! I had been struggling trying to use my other calculator that I got just because it is an approved NCEES one and I did not know much about any of the ones on the list. I got my new calculator and am enjoying learning how to use it, just wish I had had this article back then!
ok lets be honest. this is not my first time appearing for exam. but this time the way i am calculator is like i have never used it before. Zach without your info on calculator i would have made the mistakes again….. despite having calculator i still use to calculate on my own not knowing that my calculator functions and trick can save me so much time. Gosh i feel so stupid now looking at how i use to mess up exam problem just because of calculations. awesome work zach.
No problem Shubpreet! Glad you learned the tricks and time saving techniques now before the exam so that you can use them to your benefit during the PE exam.
While doing practice problems for the PE exam I found that I was making a lot of mistakes on my Casio FX 115ES calculator. This article solidified my choice to purchase the TI 36X Pro! I’ve found that I’m not making any mistakes using this calculator and it’s more intuitive to use. .
Hi Zach – anyway that you could post a tutorial video walking through the complex number capabilities of the TI-36X Pro like you did for the TI-30XIIS?
Hi Michael,
We will be adding more calculator videos in the future to our free youtube videos and articles. In the meantime however we do cover how to best use the TI-36X Pro for all subjects during each online live class included in our program.
This was probably one of the most helpful articles here. I can understand and re-learn the math concepts contained elsewhere on the site but if I can’t quickly and reliably work the answer on the calculator then I effectively am wrong. The guidance here lead me to be more effective in my working of problems allowing me to focus on the CONCEPTS and not the button pushing!
Ive been using this calculator for a while but the unit conversion, fraction, and percent key you showed us in the Fall 2019 live class saves a lot of time and errors.
Thanks Zach
Zach –
I passed the EIT my senior year and got my PE about 4 years later. In 1974 I was able to get a SR-50 TI. It was great because I could do Polar to Rectangular conversions and back w/o the slide rule. I wish I could have had the TI-36X Pro back then. I worked through your example both with the TI-36X and long hand.
I think your article is excellent and should be included in any pre-engineering course.
Good luck.
Thanks for sharing Joseph, glad you enjoyed the article.
I’m a TI-36X Pro guy myself! Definitely can’t go wrong. Honestly your comment response where you explain how to input “angle” in a TI-36X should be part of the main article, I’m reteaching myself how to use the TI-36X PRO and that was the first question I had. Pretty intuitive once you know how to do it.
Ok, typo check time. 😀
“Using a calculator that can’t use both polar and rectangle at the same time (most can’t), you would have to manually convert your values SEVEN TIMES before getting the right answer…”
Should say “rectangular” instead of “rectangle”
“5. To add this value you I2 you would have to convert it to rectangular”
Should say “…this value to I2 you would…” instead of “you I2”
Later in the TI vs. Casio…
“TI” is not capitalized right in the header.
“Growing up in the American school system they were almost always the default brand used making Ti calculators much more intuitive to use and less of a learning curve compared to Casio models.”
Need to capitalize “TI” again
Missed capitalizing Android two sentences down… and Amazon shortly after that, in two places.
Finally, near the end:
“But consider how silly you would feel if after all of your hard work and financial investment to take the PE exam you end up with a dud of a calculator after the exam starts all because you didn’t take a $20 dollar back up.”
Should delete “dollar” after “$20” as it’s redundant.
Great article as always!
You are on a roll with these corrections Josh, a big thank you! These have all been corrected.
Every live class is taught with the TI calculator shown on screen, I’ll be showing you all of my tricks and time-saving tips for every subject so you will be well prepared once it’s time to take the exam.
I personally am loving the TI-30X Pro (MathPrint) calculator. The main reason is I can quickly change the “mode” the calcular from answers in Polar to answers in Rectangular (or vice versa)…then just hit enter to do a quick conversion. No need to find the magnitude and angle in separate functions/steps. It was a bit pricier at $35-40, but if cost is not an issue then it was definitely worth it. It also has a lot less lag time in computing answers (not that the 1 second delay is major, but hey…it adds up). Just another option to consider as you find the right calculator for you.
If cost is not an issue, which calculator is better for the PE exam: the TI-30X or the TI-36X Pro? Are there any significant differences in functionality between these two models?
You say ‘Enter the following equation and press enter:” to show the TI can convert as you describe. ….How do I physically enter that string into the TI?….I don’t have those buttons on my calculator…