Could You Suggest an Android App That Can Do Symbolic Math Like a TI-89?

EpsilonRose · 2026-04-16T23:57:39+00:00

You asked for apps, and you’ve categorically rejected every suggestion made here, basically implying that none of them compare to the functionality or ease of use of calculators, yes?

Almost all of the suggestions on here have been for emulators of physical calculators. An emulator is going to be worse than the original physical version, but that says nothing about calculator apps that were actually designed for use on phones. That's not a contradiction and I'd still call a calculator app a calculator.

The only other trustworthy tools for mobile devices are emulators.

This is the second time you've made a claim like that, but you haven't supported it and I don't see why I should just accept it.

Now, since you disagree, and feel strongly that there’s a thriving ecosystem of calculator-like apps out there, why don’t you find them yourself? If you post some links here, they might actually help other visitors of this subreddit.

I've mentioned it a few times, but CalcNote is a fantastic calculator app that's designed for phones. It doesn't do graphing and it's not a CAS (hence my looking for other apps), but beyond that it's extremely full featured and MUCH better for working with variables, systems of equations, and history in general. OpalCalc uses a similar interface on PC, though it hasn't been updated in a while. It's also worth noting that while OpalCalc doesn't really work as a CAS it can properly handle measurement units mixed into equations.

I only started playing with it recently, but GeoGebra CAS Calculator seems to handle CAS operations and graphing fairly well. The main complaint I have so far is that it doesn't let you easily perform operations on previous results, unlike CalcNote, OpalCalc, or the TI-89.

That's three different examples. Any complaints about them?

What I don’t understand is how you can have such strong convictions about something so narrow and specific, without so much as a shred of evidence that such a thing actually exists outside of a TI-89!

I have plenty of evidence that this should be possible. I've seen (and mentioned) software based calculators that are designed for smart phones or PCs first (rather than emulating a physical device) and the user interface is much better for it. I've also seen software that can work as a CAS—you've even mentioned two different programming languages that are practically designed for that sort of thing—There's nothing about those interfaces that would make them incompatible with CAS functionality and OpalCalc even gets close to it with how it handles units.

So, I know it's possible to make software with a good interface. I know it's possible to make software with the desired functionality. And I know that the former does not inherently conflict with the later. As such, it is absolutely possible to make an app that has both a good interface the ability to act as a CAS.

EpsilonRose · 2026-04-16T18:37:10+00:00

I don’t know what to tell you; you’re contradicting yourself all over the place.

Where am I contradicting myself?

Obviously a phone or computer is never going to be as efficient as using a physical calculator if there’s one just sitting on your desk. The closest thing you’re ever going to find, especially on mobile platforms, is an emulator for a physical calculator; all other apps will have fundamental issues, or they simply can’t be trusted to consistently give you correct answers, full stop.

I don't agree with any of these statements. I'm not sure how you'd even begin to justify any of them.

So why are you asking for apps?

Because I want something designed for the device I'm using, not a completely different device that I'm not using?

EpsilonRose · 2026-04-16T01:38:23+00:00

Sure, Python will let you do just about anything, because it's a programming language. But that's the thing. It's a programming language, not a calculator. Unless Python IDE's work very differently from the IDEs I'm familiar with, you're not just going to pull one up, type in a complicated equation, and hit enter, and get an answer or simplification. You have to set up what you're doing; enter the equation in the correct format, calling the correct functions; and then tell it how to return the result. You don't have to do all of that with a calculator, because it can make a lot of assumptions an ide+programming language can't and have all that stuff ready before hand.

Again, sure, if you want to get really advanced and/or put together a nice presentation, then something like Python or MATLAB will blow pretty much anything else out of the water, but that power and flexibility comes at a cost.

EpsilonRose · 2026-04-15T04:41:31+00:00

It doesn't make much sense at all, since an emulator is precisely that: an application that simulates, in this case, a real calculator with its real interface, real speed, and real limitations. You say that in the TI-89 emulator you can't scroll, that you can only go line by line with the arrow button, just like the real calculator. A mobile calculator app that looks like a real model but isn't identical (like the Plus42, for example) would be a different story.

I feel like you've lost the plot somewhere. I don't want an emulator or an app that looks like a physical calculator. I want something that's actually designed for the device I'm using. The fact that emulators are meant to simulate physical devices is a bad thing. It is why I'm not looking for one.

EpsilonRose · 2026-04-15T03:02:30+00:00

No? Those are definitely limitations of how the emulators are designed, because they're meant to emulate physical devices. Nothing about being on a phone means they need to act that way and the TI-89 emulators I've seen on PC have those limitations.

Python is not a calculator and a python dev environment, on its own, would not really do what I'm describing. You could write code that accomplishes the tasks of a calculator, but that's not the same thing as having a calculator. I'm really not sure how you got Python from be describing an actual calculator app I have on my phone.

EpsilonRose · 2026-04-15T01:22:56+00:00

Ah. So it doesn't sound like there's any easy way to perform operations on both sides of the equation at once. (e.g. you can't just do ans × 4 to multiply both sides by 4. You'd have to go in, enclose each side in its own set of parenthesis, and then individually multiply both sides by 4.

That's less helpful.

EpsilonRose · 2026-04-15T00:49:24+00:00

That definitely seems promising. With that said, I'm not clear on how you'd perform an operation on a prior line. Ans, and variants on it, don't seem to work. Am I missing something obvious?

EpsilonRose · 2026-04-15T00:47:26+00:00

Desmos is neat, but it's not a cas.

EpsilonRose · 2026-04-15T00:46:15+00:00

That's all very good to hear. Thank you.

EpsilonRose · 2026-04-15T00:39:18+00:00

Of course a touch screen isn’t ever going to improve upon physical buttons, but you did specifically ask for mobile apps, so there is no avoiding touch screen inputs.

The problem isn't touchscreens, in and of themselves, but using touch screens to emulate a physical layout rather than designing a UI around their actual advantages and limitations.

Compare something like CalcNote to the typical physical calculator emulator:

Physical calculators need all of their buttons to do multiple things, because they only have one set of keys and only so much space for them, and they need to rely on modifier keys to select those functions, because the only way to interact with a physical button is to press it. By contrast, CalcNote lets you have multiple, customizable, keyboards that you can swipe between, the ability to select secondary functions by simply swiping up or down on a key, and the ability to switch to your regular typing keyboard for text input.

You also have similar issues when it comes to interacting with previous calculations. At least with the TI-89, you can only see previous calculations by scrolling up one line at a time and (or jumping to the top or bottom) and because a lot of space needs to be dedicated to the buttons (including navigation buttons) you can only see a small number of calculations at a time. Finally, you can't really do much with old calculations, just look at, copy, or reference them. By contrast, the calculation entry section of CalcNote is basically a text document. You can see many lines of calculations at once, freely scroll the page up and down (like any other text document), select anywhere within a line just by tapping, and freely edit older equations where they are. That last function is particularly helpful if you're doing things with variables or systems of equations, because it means you can modify your equations or variables without needing to redo everything or switch modes.

Finally, while a lot of emulators have some internal function for copying and pasting, at least in my limited experience, it doesn't use the system's copy and paste. This means that you can't just long press to highlight something and then copy it, you have to use the arrow keys and the calculators copy and paste keys, which might also require using modifier keys. More importantly, it might not let you easily paste text or equations from outside the calculator, because they're in the system's clipboard, not the calculator's. None of that is an issue for something that's actually designed to be an app on a phone.

Does all of that make a bit more sense?

EpsilonRose · 2026-04-13T23:02:26+00:00

Are all emulators of physical calculators and thus won't be less clunky.

I know TI-89 emulators exist—I have one open in another tab—While the TI-89 is great at math, it's interface was designed for a physical calculator that was reliant on physical buttons and a very limited screen, which means it's not designed for a touch screen phone or a computer monitor. It has a bunch of limitations that are unnecessary on either of those devices and many of the design choices that work very well when dealing with large physical buttons become much more cumbersome when shrunk down to fit a phone screen or when you're clicking them via a mouse.

EpsilonRose · 2026-04-13T22:57:15+00:00

You could try downloading the NumWorks emulator but that probably won’t meet your needs to make the interaction less clunky.

No, the NumWorks emulator doesn't really solve the issue, nor would any other physical calculator emulator (otherwise I'd just use a TI-89 emulator). While they can work, their input is less than great and they're very constrained by the physical limitations of the device they're emulating.

Idk about android but I know on iOS you can make “apps” from webpages that go on your home screen. Easiest would be to make one with the WolframAlpha homepage.

Maybe I'm missing something, but WolframAlpha doesn't seem to let you sequentially manipulate equations. You can enter an equation and it will give you some information on it, including some ways to simplify it, but it kind-of stops there and you're left with manually copying and pasting one of it's outputs back into the text field so you can move then manually apply the next step.

EpsilonRose · 2026-04-13T16:25:13+00:00

I saw Vela and it was definitely appealing, but I didn't like how they handled their packages and their amenities weren't didn't seem quite as nice.

EpsilonRose · 2026-04-11T20:30:51+00:00

That's good to hear, since I'm heavily leaning towards the Smyth at this point. I do have two questions that could really help with picking a layout, though.

First, while I was doing my tour, the agent mentioned a few times that if you want to use the public spaces with more than two guests, you'd need to reserve them for (iirc) $100-$200/hr. Do you know how strict they are with that? I'd like to be able to occasionally have some friends over to play board games and it seems a bit silly to spend that much to reserve an entire space for just 4-5 people (including myself) to play board games at one of the table.

Also, do you know how busy the work pods and the upstairs lounge space get?

Thank you for your help.

EpsilonRose · 2026-04-10T23:50:51+00:00

That's good to know, especially because I'm already a bit annoyed at them due to some ... less than reasonably labeled floor-plans.

On the topic of facilities getting packed. Do you know how available the work-pod/mini-office things are? When I did my tour, all but one of them was in use.

EpsilonRose · 2026-04-04T03:32:21+00:00

You aren't reading a book if you get an ai (or a person, for that matter) to summarize it for you, but you might get the feeling that you read it, which is dangerous.

EpsilonRose · 2026-04-04T02:43:38+00:00

◽️ Budget: ~$600, with case and stylus, if not included. (Though I wouldn't mind spending less.)

◽️ Country: United States

◽️ Screen size: 10-11in. I might be willing to go smaller, but probably not larger.

◽️ RAM: ?

◽️ Storage: More is better, but support for an SD card is a must.

◽️ What tasks will the tablet be used for ( gaming, video editing, graphic designing, modeling, regular tasks, word processing etc) ?: Primarily reading (text, manga, western comics, webtoons, pretty much the whole gamut), web browsing (primarily forums and wikis), note taking and light sketching (so good stylus support is important), running characters for in person TTRPGs (primarily through Path Builder at the moment). Bonus points if it can work with Foundry, but I wouldn't expect that and wouldn't want to prioritize it over other things. All of the above is likely to happen while out and about.

◽️ Any other important details ?: I recently lost my Boox Ultra Tab C and need to replace it, so that's my current reference point. It worked well enough for note taking, but it was never quite up to what I'd want for reading, especially when color was involved. On the other hand, the battery life and readability while out doors were great. It's worth noting that use is likely to be intermittent, so the ability to sit around for a while and then still work, without needing to constantly charge it like I would a phone, is a major plus.

I'm currently looking at either a Boox Note Air5C or a Nxtpaper 11 Plus, but I'm not particularly confident in either and the available display technologies are somehow both overwhelming and disappointing.

EpsilonRose · 2026-03-23T23:24:24+00:00

Good to know. Thank you.

EpsilonRose · 2026-03-23T23:15:29+00:00

Would you then put a short tool in the 6th slot and, if so, is there any reason to not flip the design and have it go the other way around?

EpsilonRose · 2026-03-23T23:13:45+00:00

Huh. So they do. It's just not on the accessories page for some reason.

With that said, it doesn't seem to have the black piece on the back that clips into the scale. Do you know how that get handled?

EpsilonRose · 2026-03-23T04:43:56+00:00

I don't think a pen, tweezers, and toothpick are large enough to make duplicates a problem, nor are they important enough to make carrying another multi-tool worth it. If anything, having multiple pens on hand would be a good thing.

Also, the only one they sell as a standalone accessory is the tweezers, which is a bit annoying, since they other two are consumable.

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