TI-36X Pro: Best bang for your 20 bucks

[Dave Britten]

Last week I needed a cheap calculator for doing regressions other than the basic four that the HP-48 is equipped with, so I grabbed a TI-36X Pro. Bottom line: despite being a barbaric algebraic monstrosity, you won't find a better calculator for the price.

Calling this the TI-36X Pro is rather misleading, because it's not even in the same league as the 36X, which was a functional, yet completely unremarkable scientific. The Pro has been upgraded with a dot-matrix LCD, and functionality that actually makes it a closer contender to the TI-83 and 86.

Most importantly, this is an "almost programmable" calculator. It doesn't give you any ability to write imperative programs, nor does it have functional programming like the 17BII solver. Instead, it has three neat features: set-op, list functions, and function definition.

Set-op is extremely simple to use. You press 2nd set-op, and at the prompt, type any expression or commands you want to evaluate, then press enter to save. Now on the home screen you can press 2nd op to execute that fragment either with whatever you've started typing already, or the value of Ans if the command line is empty. This is particularly useful if you need to do a bunch of conversions. Use set-op to enter ->Hex, ->DMS, a unit conversion, or whatever, then you need only enter an input and press 2nd op to repeat the calculation. If you use op repeatedly on the previous answer, a counter will increment showing the number of iterations (n=1, n=2, n=3...)

Function definition is similar, but allows you to define f(x)=expression. Then you can insert f(x) anywhere in a calculation to evaluate the function, or view a function table to explore multiple values.

The calculator gives you 3 lists for entering data, which can be used for statistical calculations. You can define any of these lists to be calculated based on values in the other two. If, for example, you're entering x values as time in H.MMSS format into L1 to save time during entry, and you want to convert these to decimal hours for calculations, you could define L3=iPart(L1)+iPart(fPart(L1)*100)/60+fPart(L1*100)*100/3600 and have L3 updated automatically. You would then use L3 for x values in any statistics, as the calculator allows you to select which list is x, which is y, and which (if any) contains frequencies).

The multi-tap keys are a cool idea to pack a lot of functions on the keyboard without a squadron of shift keys. For instance, there's a key labeled "sin sin^-1". Press it once to enter "sin". Press it again, and the function changes to "sin^1". Two further presses will get you "sinh" and "sinh^-1". Quite a few of the keys work this way, including trig, logs, powers, and probability.

Other features:

• Battery (CR2032) + solar dual power
• 8 storage variables (x, y, z, t, a, b, c, d)
• MathPrint mode, which displays properly formatted expressions as you type (think HP 48 Equation Writer), and is optional
• A few CAS-like features: fractions, square-root simplification, fractions of Pi
• Numeric integration and differentiation
• 1-or-2-variable stats
• Statistics distributions: normal, inverse normal, binomial, Poisson
• Regression: linear, quadratic, cubic, ln, power, exponential
• Matrix math (3 matrices, max dimension is 3)
• Vectors (3 vectors, max dimension is 3)
• Complex numbers
• Fraction conversion
• Base 2, 8, 16, Boolean logic operators
• Probability functions: factorial, nCr, nPr, random numbers
• Polynomial solver (quadratic and cubic)
• Numeric solver (separate equation, but you can use f(x), e.g. y=f(x))
• Linear system solver (2x2 or 3x3)
• Physical constants
• Unit conversions
  

Minor gripes:

The basic arithmetic operator keys are silver, and rather than having the symbols printed on the faces, they're molded slightly into the plastic. This is almost unreadable in any lighting conditions. Take an ultra-fine-point Sharpie and color them in, and it looks great. "Enter" would be hard to fill in because of the relatively light font, but you probably won't need to relabel that one.

Unit conversions are... functional. Definitely not too impressive, though, compared to all the other features. You've got 9 English/metric conversions (all two-way), conversions between F and C, or C and K (no Rankine?), 4 speed/length conversions (again, two-way), and pressure conversions between atm and Pa, or mmHg and Pa (no PSI?). I would have liked to see this more like the TI-86, where you have multiple categories of units, and can convert between them freely. Getting from gallons to cubic feet on the 36X Pro is quite a chore. (Convert gal to L, multiply by 1000 to get ccs, take the cube root, convert to inches, divide by 12 to get feet, then cube.)

Set-op being a shifted function is fine, but having "op" on a shifted key is disappointing. I think it would have made more sense to rearrange some of the functions on the keys just above the digits to get "op" a primary function, and make the fraction (x/y) function shifted. The 34 Multiview has TWO of them, op 1 and op 2, both unshifted, although it doesn't have to pack nearly as many functions onto the keyboard.

I love the list function feature, but if you try to define one and reference another list that doesn't have any data in it yet, you get an error. The same thing happens if you clear a list referenced by a list function: you get an error, and are forced to clear the formula. Keep a reference sheet handy if there are formulas you use frequently (like the decimal hours conversion) since they won't survive clearing of the referenced list.

Honestly, they should have called this something else, as the TI-36X Solar is a comparative weakling.

[Tugdual]

Made in China... Looks capable but somehow weird spec, who would use that calculator? Somehow looks like a 35s low spec clone. Wonder if that is a 6502.
Is TI also going for Kinpo?
Some pictures here

Eddie did a review here

Edit: datamath confirms it is Kinpo.

[Dave Britten]

(05-31-2015 08:43 PM)Tugdual Wrote:  Made in China... Looks capable but somehow weird spec, who would use that calculator? Somehow looks like a 35s low spec clone. Wonder if that is a 6502.
Is TI also going for Kinpo?

It's got almost nothing in common with the 35S. The 36X Pro has a lot fewer bugs, for starters. No clue on the CPU; datamath.org indicates it's a chip-on-board epoxy blob, so there isn't anything to ID it. If I had to guess, it's probably Z80 like the graphers.

It feels more like a slimmed-down 83. I'm pretty impressed with it so far. There are better, more powerful options out there, but not for $20.

[Steve Simpkin]

The SHARP EL-W516 and the CASIO fx-115ES calculators are very comparable to the TI 36Pro.
http://www.hpmuseum.org/forum/thread-815.html

[Dave Britten]

(05-31-2015 09:01 PM)Steve Simpkin Wrote:  The SHARP EL-W516 and the CASIO fx-115ES calculators are very comparable to the TI 36Pro.
http://www.hpmuseum.org/forum/thread-815.html

The Sharp and Casio models look decent, but it seems like the Casio is more limited in what it can do with lists, and the Sharp doesn't appear to use lists at all.

[Steve Simpkin]

Some additional information on these models.

Casio vs Sharp vs TI:
http://members.bex.net/jtcullen515/Math8.htm

Eddie's Math & Calculator Blog - Review of the TI-36 Pro
http://edspi31415.blogspot.com/2011/04/t...w.html?m=1

[kharpster]

I have a TI 36X Pro, it is a nice, but for the money I will take (and did) the HP Prime Android App.... ;-)

[CR Haeger]

Dave,

Thanks for the excellent review and your thoughts on this calculator. I agree that it's a really good value at $20. I have used one for about a year and my teen daughters use this often in place of a grapher - mainly due to its ease of use and test acceptance.

Although my history (and heart) lies with HP RPNs, this algebraic with mathprint is dead simple to use or construct an expression. I find being able to scroll up to review and/or click to copy earlier expressions a great and oft used feature. I agree that the multi-tap keys reduce keyboard clutter and are easy to use.

Set-op is useful as you stated and I had not thought of saving a set of conversion instructions - thanks. I did setup a quick and dirty Newtons method solver using: op=*0+x-f(x)/d/dx((f(x))|x=x→ x (where sto→ x stores initial guess)

I use the table f(x) often as it can be used almost anywhere else in the calculator. table 1 x is in my muscle memory at this point.

data lists is very flexible as you stated. Note that besides L1-L3, f(x) and x-d variables can all be used here.

On convert, I agree that getting from one unit to others or linear-area-volume are not always easy. You can raise the conversions to powers, like 1 m>yd^3 1.31.

Check out stat-reg, poly-solv and num-solv, all which guide the user to the desired operation and offer to save variables and/or results.

Finally, the numeric differentiation and integration are easy to setup and run.

Enjoy exploring!

[Dave Britten]

(05-31-2015 11:47 PM)CR Haeger Wrote:  Although my history (and heart) lies with HP RPNs, this algebraic with mathprint is dead simple to use or construct an expression.

Definitely. Usually I don't care for that sort of entry method, but it's nice and responsive here. It saves you the trouble of remembering number and order of arguments for various functions (nDeriv, sigma, etc). Just put them where they'd go on paper!

[Nigel (UK)]

(05-31-2015 07:44 PM)Dave Britten Wrote:  Last week I needed a cheap calculator for doing regressions other than the basic four that the HP-48 is equipped with, so I grabbed a TI-36X Pro. Bottom line: despite being a barbaric algebraic monstrosity, you won't find a better calculator for the price.
...

What about powers-of-ten entry? I have an earlier calculator in the TI-3x series and exponents require use of a "x10^" key, where the multiplication has the same priority as ordinary multiplication and division. This means that dividing by a number with a power of ten (in normal entry mode) requires brackets, which I kept on forgetting.

Does this calculator behave in the same way?

Thanks.

Nigel (UK)

[CR Haeger]

(06-01-2015 10:01 AM)Nigel (UK) Wrote:  

(05-31-2015 07:44 PM)Dave Britten Wrote:  Last week I needed a cheap calculator for doing regressions other than the basic four that the HP-48 is equipped with, so I grabbed a TI-36X Pro. Bottom line: despite being a barbaric algebraic monstrosity, you won't find a better calculator for the price.
...

What about powers-of-ten entry? I have an earlier calculator in the TI-3x series and exponents require use of a "x10^" key, where the multiplication has the same priority as ordinary multiplication and division. This means that dividing by a number with a power of ten (in normal entry mode) requires brackets, which I kept on forgetting.

Does this calculator behave in the same way?

Thanks.

Nigel (UK)

Nope. Keystrokes

1.23 / 4.56 EE 6 enter

--> 2.70E-7

[Hlib]

CASIO fx-991ES Plus has almost same characteristics and the price. Besides, it wieghs less and more attractive in design. Therefore I got fx-991, but not TI-36.
And one more interesting thing: some definite integrals fx-991 calculates quicker, than HP-50G in EQW-mode. E.g. exp(-1/x^2) etc. (consumption within 0.001W !).

[Gerald H]

Casio fx-991 DE PLUS is even better, having GCD, LCM, FACTors & a very clever use of recurring decimals, eg 1/65 returned as

0,0*153846*

In general the TI 36X Pro integrates faster.

[Nigel (UK)]

(06-01-2015 10:27 AM)CR Haeger Wrote:  

(06-01-2015 10:01 AM)Nigel (UK) Wrote:  What about powers-of-ten entry? I have an earlier calculator in the TI-3x series and exponents require use of a "x10^" key, where the multiplication has the same priority as ordinary multiplication and division. This means that dividing by a number with a power of ten (in normal entry mode) requires brackets, which I kept on forgetting.

Does this calculator behave in the same way?

Thanks.

Nigel (UK)

Nope. Keystrokes

1.23 / 4.56 EE 6 enter

--> 2.70E-7

Thanks for this - glad to hear it.

(06-01-2015 05:16 PM)Gerald H Wrote:  Casio fx-991 DE PLUS is even better, having GCD, LCM, FACTors & a very clever use of recurring decimals, eg 1/65 returned as

0,0*153846*

Recurring decimals on Casio calculators are the bane of my life as a physics teacher. Students will write "0.*6" simply as "0.6", and will even write (for example) "0.0*153846*" as "0.0*153" if I ask them to round results to 3 significant figures. I know that this feature can be turned off but the Maths department always seems to turn it back on again!

Nigel (UK)

[Bunuel66]

"Casio fx-991 DE PLUS is even better, having GCD, LCM, FACTors "

Actually, the TI 36X Pro has also those functions...

[Lonewolf]

   

(05-31-2015 07:44 PM)Dave Britten Wrote:  Last week I needed a cheap calculator for doing regressions other than the basic four that the HP-48 is equipped with, so I grabbed a TI-36X Pro.

Calling this the TI-36X Pro is rather misleading, because it's not even in the same league as the 36X, which was a functional, yet completely unremarkable scientific. The Pro has been upgraded with a dot-matrix LCD, and functionality that actually makes it a closer contender to the TI-83 and 86.

The multi-tap keys are a cool idea to pack a lot of functions on the keyboard without a squadron of shift keys. For instance, there's a key labeled "sin sin^-1". Press it once to enter "sin". Press it again, and the function changes to "sin^1". Two further presses will get you "sinh" and "sinh^-1". Quite a few of the keys work this way, including trig, logs, powers, and probability.

Can I ask what exactly you meant by "...it's not even in the same league as the 36X, which was a functional, yet completely unremarkable scientific..."

Also, I don't know which small HP scientifics have power-off memory protection, but for me, the memory safeguard of the 36X Pro is an absolutely important software feature. I can't tell you how amazing it is to be working on a data table, or even working on vector problems, and the TI auto times-out after a few minutes of non use, but when you turn it back on, everything is like you left it. I never could understand why Casio has never implemented memory safeguard in their small scientifics.
/Silicon Valley Regards

[Dave Britten]

(09-21-2015 10:25 PM)Lonewolf Wrote:  Can I ask what exactly you meant by "...it's not even in the same league as the 36X, which was a functional, yet completely unremarkable scientific..."

Compare to its predecessor (in name), the 36X Solar:
http://www.datamath.org/Sci/Modern/TI-36XSolar_2004.htm

It was a very basic scientific. The difference between the two is like if they called the TI-92 the TI-82 Pro or something absurd along those lines.