# Trends in calculator interfaces

The trend in commoly available cheap scientific calculators is that when you want to calculate a function like sin( sqrt(2)/5) , the most convenient thing to do is press the sin() key first.

Twenty years ago (or less) when using the "algebraic" calculator interface (on some fairly expensive calculators), the most convenient thing to do was to work out sqrt(2)/5 first and then press the sin() key. That style interface was useful if you did rough estimates of the work as you progressed. You could mentally check if sqrt(2) looked correct, then check if dividing by 5 looked correct and if you were good at trig you might see if the sin() looked right. If you weren't good at trig you could trust your manual dexterity to press the sin() key instead of something else.

I think the modern trend is to check the visual appearance of the formula on the display. So you check if the display is showing a formula that is correct instead of checking that the stages in the calculation make sense numerically. People who do computer programming or even just spreadsheet programming develop skill at checking the visual appearance of formulas.

Perhaps better displays and more people who can check formulas explains the modern trend in calculator interfaces.

I'm curious whether any of the expensive Texas Instrument calculators have an option to change the interface to the old fashioned style - if they no longer use that style as the default.

Ben Niehoff
Gold Member
Calculators seem stuck in the dark ages, to be honest. I blame the stranglehold TI has on school purchases and textbook writers.

You shouldn't need a big clunky calculator just to be able to see formulas in mathematical notation, graph functions, do symbolic manipulation, limits, calculus, etc.

I have a complete version of Maxima installed on my cellphone (look up "Maxima on Android"). I don't even know how to use Maxima, it's mostly for novelty :P. I'm much more comfortable in Mathematica (who have not, to my knowledge, produced an Android version).

Such a system is much too complex for most high school math students' needs. Not to mention, high-end smartphones are quite a bit more expensive than TI calculators (although they are still selling the ancient TI-83 Plus for $100, lol...highway robbery). My point is that it is clearly possible to make a sophisticated graphing calculator in the form factor of a smartphone. And I think if the device only has to be a calculator (and not a phone, etc.), then it could probably be sold at a price point similar to current TI calculators. But they don't want to design such a device. Totally new designs are expensive; iterative designs are less so. And why take a risk when you have school districts across the country buying even your horribly out-of-date designs in bulk? I have just learned that TI does make a graphing calculator app...but only for iPads (which cost 4-8 times as much as TI calculators to begin with). jedishrfu Mentor Are you thinking of RPN vs Algebraic? Some calculators support that mode still? It eliminates parentheses. Vanadium 50 Staff Emeritus Science Advisor Education Advisor 2021 Award And I think if the device only has to be a calculator (and not a phone, etc.), then it could probably be sold at a price point similar to current TI calculators. I don't think the cost of a smartphone is driven by the phone features. I think the sort of price point we would be talking about would be of order what an iPod Touch costs, or$200.

Ben Niehoff
Gold Member
I don't think the cost of a smartphone is driven by the phone features. I think the sort of price point we would be talking about would be of order what an iPod Touch costs, or $200. But the iPod Touch, being an Apple product, is certainly priced higher than "necessary". And the fanciest TI calculators currently available go for about$170.

By "phone features" I meant several pieces of hardware, such as the cellular and wifi radios, that take up valuable circuit board space. A calculator also wouldn't need the iPod Touch's hard drive (or flash memory, or whatever they're using these days).

But I do agree I'm not necessarily good at estimating price points, especially without knowing what the actual bottleneck is in the production process. I seem to recall that the touchscreen itself is a fairly expensive part.

I wouldn't want a small touch device as a calculator. Even if the size of the touch device is large (tablet), and the buttons as large as in calculators; I still want the tactile feedback. Maybe, this just my legacy holding me back; like when the time full-touch smartphones were damned for not having physical keyboards; but now everybody seems comfortable with touch.

To the OP: I think you are looking for an RPN calculator, which is usually supported only by HP. See https://www.amazon.com/dp/B000GTPRPS/?tag=pfamazon01-20

My favorite is this, and it has algebraic input.

For anything this calculator can't do, I prefer using Mathematica in my laptop.

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Ben Niehoff
Gold Member
What if you didn't need buttons? I have an app on my phone (called "MyScript Calculator") that takes your handwriting as input. You write out something like

$$\sqrt[3]{\frac{6!}{23}- \sin (e^{3\pi})} = 3.119\ldots$$
and it gives you the numerical result (it fills in the = sign and puts the number after it...I did this example just now). It dynamically rescales things as you're writing, so you can fit all of that in. It has pretty limited functionality (pretty much everything that appears in that formula, and logs), and only shows 3 digits after the decimal point. But it is a great proof of concept. Imagine if you could couple such an input system to a full-blown CAS!

I use it for very simple calculations if I just want to know some numerical result. For most such calculations, it's much faster than punching buttons on a normal calculator.

CalcNerd
Gold Member
Maybe the BA-35 may offer that option.

There are at least 3 algebraic versions of calculator input. The first was simple chain logic ie the calculator worked on the numbers as you entered them ie no precedence:
1+2*3=9

Next came AOS which is what the first generation of scientific Texas Instrument calculators used.
1+2*3=7
and your trig example would be 2, sqrt, /, 5, sine= ###
This is still how the cheapest Ti 30xa still works and costs \$10 and is pretty well built.

Now EOS or VPAM is currently the new calculator algebraic entry. I think all graphing calculator and most calculators with a pixel display use this type of algebraic form. Basically you enter the equation in the same order as the textbook. Often these types of calculators are very particular about parenthesis as would be expected. You need to see the function is equal to the printed form.

There are subtle nuances to EOS vs VPAM used by earlier Casios which give precedence to implied multiplication (something I personally feel is best), but this type of reasoning is now considered wrong and all multiplication and division is now operated on in a left to right manner.

jedishrfu
Mentor
Another unique calculator app is pi-cubed on ipad

CalcNerd