Ask HN: Do you still use physical calculators?

I have an old HP 15C RPN scientific calculator.

- I know where the buttons are without looking.

- It has functions my Android calculator does not have (directly or that I know of).

- It has a strange satisfying tactile feedback.

- It never interrupts me. Ever.

- It never distracts me. Ever.

I reach for it frequently.

Yes, I have a Casio fx-9750GIII and I love it. I still haven't found an Android app or website that can do everything that I need (basic functionality), but in general:

- I need physical buttons. I often find that on touchscreens I mistype something and I don't notice.

- The history feature. Maybe I want to do a serial task or calculation, and I can just replace/correct one of the formulas in the history and it automatically recalculates all of the expressions that came after it.

- I have written some micropython code / utilities for the calculator and I use it all the time.

- I don't want to context switch to do a quick calculation. On my PC I have to open up a new terminal or a website (I might be offline, so I have to hotspot and then connect the wifi and ...) and interrupt my existing work or I have to frequently switch between a PDF or latex or whatever that I'm working on.

- Typing out `sin` or `np.sin` or `sin^-1` on PC is both longer and more error prone. It gets very frustrating very quickly.

- The numerical solver is a godsend. Try solving for the roots of an expression like `xe^x = 10` on your PC without internet. Or with an android application. On my calculator it's just a few dedicated button presses. On the PC, I have to use isympy and typeout `nsolve(Eq(x * exp(x), 10), 1)`, and you wouldn't even get a proper graphical display of the expression while you are typing it.

- I have a HP 16C, mainly for doing number conversions (DEC-HEX-BIN) and binary arithmetic.

- I have a HP 15C to take with me all the time (due to its small form factor).

- I have a HP 48 GX as main calculator, it is most feature complete and has a clock and alarms. I use it a lot for time calculations.

- I have a HP 48 SX, but did not use it much any more after acquiring the 48 GX.

- I have a HP 10bII+, which was a gift of my brother in law when he saw my obsession with HP calculators. I do not use it much, as I am not in financial stuff.

- I have a HP 41 CV, which is less capable as my 48 GX, but I somehow love it so much, that it resides on my desktop and is used a lot.

- I have a Casio Classpad fx-CP400, which I use when I tutor my nephew - it is the best fit for high school requirements (in Germany).

- I have a bunch of TI nspire and voyagers and a TI 83 plus, that I never use.

- I have a TI-92 plus which I used a lot in the past, but I do not like it anymore.

- I have a Casio FX-730P, which I like to write little programs for.

Not to mentions my collection of slide rules.

I use a junky $5 calculator when I'm working with my mill and lathe. It's easier to have the little thing there at hand in the machine shop to do quick calculations than to have a whole computer.

I have a Swiss Micros DM42, a modern clone of the HP42s on my desk and I have the plus42/free42 app on pretty much every device I own. Stack based calculators are great because the stack works as a little scratchpad when I'm trying to figure something out.

If I'm solving a problem of any complexity I'll move to a more appropriate tool like python or a spreadsheet, but for the simple math that needs to be done around the edges personally and professionally, I like a calculator. If I'm at my desk, I'll use the physical version.

I think you accidentally a verb.

But, yes. Casio fx-991EX. It's designed for schools, I think, but at the time it was the most advanced one they made that wasn't a graphing calculator, since I figured that if I ever wanted to draw a graph I'd just fire up "Grapher", which is still bundled with every Mac.

In about a decade I think I've done that once. The Casio is great.

Looks like it's discontinued now? I guess the fx-9910CW is the replacement. They made the buttons circular. Weird.

There's a farm here in Zurich where we buy a lot of our groceries. The store is unmanned. You use their calculator (or your cellphone calculator) to add up what you're buying then use your phone to scan a QR code and pay.

I'm using a HP48G. [0]

It's just a joy to use and i also like it a lot design wise.

I like that it has a big display for 4 RPN rows, but i admit that that's something software calculators would even be better at.

It definitely has a nostalgic/romantic side to it for me.

Oh and for every day stuff, i really like to use Spotlight on macOS. It's really convenient: Command+Space, then just type the expression into the search box.

[0] https://en.wikipedia.org/wiki/HP_48_series

The first time I went to China and spoke basically no Mandarin (just "want", "don't want", "this one", "that one", "how much money", "thank you") I took a cheap calculator when I went shopping for electronics and just let people type in the price they wanted. It was also useful for haggling too.

> I’ve noticed that most physical scientific and graphing calculators are easily outdone in terms of performance, capability and ease of use by the likes of Desmos and the default calculators on OS’es like the iOS, Android, and Windows.

This does not fit my experience. Physical calculators still excel with respect to handiness, and are in my experience typically more convenient to use than these bad default calculators.

The tool that rather made me mostly abandon physical calculators (except if one is forced to use one, like for some kinds of exams) is rather Wolfram Mathematica.

This program is so much more capable (a complete different league) than what every physical calculator that I am aware of has to offer that convenience and handiness of a physical calculator does not matter anymore for the comparison: Wolfram Mathematica is compared to a physical calculator like what a physical calculator is compared to doing all comparisons by hand.

I have a fantastic French calculator from Numworks (https://www.numworks.com/). The problem is that it is always discharged...

For quick conversions → Chrome address bar (10 USD in EUR, 1.82 m in inches, ...)

For additions, multiplications, substractions and divisions: my android built in calculator because it has a large display and it is independent from my monitors

For advanced calculations, Wolfram Alpha ← it is really good (when it understands what I men which is often, or otherwise ChatGPT as below). The only problem with this one is that it is greeting me with emojis, cracking some jokes and generally tells me about his life before telling me how long)

Or recently ChatGPT/Gemini ("200 MB on 140 Mbps how long")

My physical calculator has something that no soft-calculator will ever have: tactile buttons and years' of muscle memory. Sure, I could put in the time to learn a soft calculator but the clunkiness of using the UI of something like Desmos (especially on a touch-screen) vs the dedicated physical buttons on my Casio make it very unappealing.

It's a similar argument to the touch-screen vs. physical buttons debate in car dashboard design (but hopefully with fewer fatalities): A button I can feel (and that never gets moved around the interface overnight due to some cargo-culting UX dev) wins every time.

During my bachelors, I was using a Casio FX-991ES+. It was a beautiful calculator compared to the hand-me-down Fx-82 VPAM. And pretty popular with the folks of my age that time.

During and after grad school, I was using Mathematica or NumPy/Sympy quite a bit. But it felt like using an overpowered system to do basic assignments. Think of taking a Bugatti Veyron for grocery shopping. I indulged myself with another physical calculator - this time a Casio FX-CG50 with a color display and python support. I use it whenever I do self-paced courses or reading the occasional stats/ML paper.

TI-30Xa still sits on the corner of my desk along with a pen and small notepad. I use it 2-3 times a week. Still faster to reach for it than find the calculator app on my phone or PC for simple tasks.

Oh dude, no. The instant I could start using something like https://www.wolframalpha.com/ in college over a decade ago, I did. I've never, not once in my life, had any desire to use a physical calculator when I could use a full blown computer instead. I think it's inferior even for pedagogy purposes - I can't screenshot and make Anki cards out of a TI-84.

Yeah I still use my good ol' TI-83+ occasionally, but I'm a math instructor, so obviously. Most often I'll just use GNU `bc` though.

We are getting away from them in the classroom though; just started piloting a program where students use the Desmos app on their phones (requested to be in airplane mode) in class, and we have a department set of air-gapped phones with Desmos pinned for students to use on exams.

I tutor advanced math and science and so have updated my daily driver along with whatever students were most likely to come across. In the past it was a ti 84 and then ti 89 titanium. But in the last decade schools have also embraced Desmos, a simplified version is even accessible on their standardized tests now.

For personal use, I have an android emulator that runs TI 89 titanium. It hits the sweet spot for me in terms of completely covering basic and advanced features I would need from a calculator. If I need something extremely basic, I use the one built into Google search. If I ever feel myself limited by the 89, it's always been because I am trying to do something that would be better served by Excel or Desmos.

The best calculator is the one most easily available. I personally don't see value in keeping a separate device. On the other hand, I will go out of my way to make sure the keyboard I am using has a dedicated numpad. There's nothing that comes close to the efficiency of tactile keys when it comes to doing long numeric calculations.

My HP32s from ~40 years ago still resides on my workbench where I mess around with RF circuits for fun. It has no graphing capability and it's barely programmable, but that's ok, I keep an actual computer nearby for those sorts of things. The calculator keeps earning new batteries bc tinkering with analog circuits I frequently want to evaluate little things like AB/(A+B) or 1/2piF or (1+S)/(1-S), or need the log 10 or square root or the cosine of something.

In those circumstances, the calculator's compact form factor is quite convenient, compared to needing two hands at the computer keyboard, or one handedly hunt-pecking said keyboard. As for the mouse, that has to be the slowest, most focus stealing option of them all. The calculator doesn't take much room, so it can be kept within arm's reach without getting in the way, quickly gives me the numbers I need, without demanding I become fully engaged with it.

Also, those old HP buttons are just so nice to press, a refreshing break from the dead flat glass you get everywhere else these days.

I have Sharp EL506T and it serves me well. I don't use it very often, mind, but it still happens semi-regularly.

The biggest reason for me are physical buttons and the fact I know the layout and capabilities. I'm just faster on physical calculator than on Android app.

But to tell the truth, usually I just use Speedcrunch on my computer. Or spreadsheeds. Or Python REPL.

I saved a scientific calculator in 1994 just in case. I never used it, as a PC was always on since then.

Today two cheap calculators are available to my children mostly as an example of "productive technology", in contrary to modern devices. This falls under a general effort to expose them to productive paradigms of 80's way of life.

No, Python or units[1] is always a better choice if I'm near a computer (and I nearly always am these days, unfortunately, I suppose). I do have three wonderful slide rules, though.

[1]: https://www.gnu.org/software/units/

- I use my HP Prime at work almost daily and I love that it has a touch screen where I can quickly copy paste past calculations. This in my opinion is better than using a stack calculator and RPN. There are also some small programs I wrote for like calculating parallel pairs for a given resistor value, based on E-Series since calculating resistors for stuff is quite a standard thing for your day as an hardware design engineer.

- I also have a Casio fx-991ES Plus which I bought during my student years and love to use it, because it is way faster for quick stuff than my Prime and I changed its battery in the past 10 years just once. This is not the case for Prime where I have to charge it every week or two. But doesn't bother me. Prime is an amazing calculator.

For over a decade I've been using emulators of the calculators I grew up using on all my android phones. I see no point in changing my "weird" ways.

I use RealCalc for most things (RPN style). Has many functions like a scientific, but I mostly stick to the basic four and it also converts units.

I switch to Graph89 when I need a graph/table involving trig or polynomial approximations. Sometimes I'll even write a basic program. If I'm using this app I probably also have measuring tools out for a DIY project.

I go to spreadsheets for anything beyond that using "Office: Planmaker". It handles the xlsx format perfectly! That's how I do my monthly budget, health tracking, etc. For reasons beyond my understanding, some people are still impressed seeing proper full-featured spreadsheets done quickly on a phone.

I don't, but I sometimes see them used here in Japan. Some small-shop operators use them to add up charges and show the total to the customer. I was recently in the office of a small company, and I noticed that the bookkeeper had a calculator next to a pile of paper (receipts?) on her desk. She also had a computer in front of her with a spreadsheet on the screen.

When I moved here forty-three years ago, it was common to see abacuses used in similar situations. There's still an abacus school [1] not far from where I live, but it's been a long time since I saw one in use.

[1] https://maps.app.goo.gl/nvTg4hfSjTcba47c8

My 30-year-old TI-83 from college is still chugging along. My kid uses it for school. Math homework is all pencil and paper so having a physical calculator is more convenient. It’s portable and dedicated to a single use that it does very well.

HP-42S; cold dead hands; etc.

Why?

Satisfyingly-clicky real buttons in memorizable positions

Easy to grab without thinking

I have a functionally identical emulator on my phone, which is far better than the built-in calcualtor, but it's a supremely dissatisfying substitute for the real thing.

I still have a cheap Casio I use from time to time. Using it to calculate logarithms using only multiplication to the 10th power and the occasional divide by 10 was a calming thing to do over lunch in the gear shop without Internet access.

Start with X. If 10 or more add 1 to the log10 for each decimal If smaller than 1, subtract 1 each time you multiply by 10.writw that down plus a decimal point

Now the fun part, the fraction of the logarithm

Hit multiply 9 times then equal, to get the 10th power on the Casio

Each time you divide by 10 to get it back into range between 1 and 10, add 1 to the fraction

Repeat until you've got enough digits

PS: it also works for binary or any other integer base.

Yeah, there’s something convenient about a dedicated device when you’re using a notebook and pen and your only other screen is your phone. It’s also nice not having to dedicate screen space to a calculator too.

If I have something more complicated with more moving pieces and data points I will just write a python script.

I like the CASIO fx-CG50, is good but there are more feature rich calculators out there, it’s just less finicky than my more powerful TI-nspire CX II one. I also just kind of dig the aesthetic of the UI reminds me of my old Nintendo DS.

My TI one is good for verifying algebraic substitutions as it’s a proper CAS one.

Nope, spotlight search handles basic calculations, python repl the rest of them.

I use TI-36x on my desk however recently I’ve been using Julia, Pluto and a combination of Handcalcs.jl and Unitful.jl for engineering calculation with a lot of success. Very ergonomic for that type of work.

I own a handful of TI calculators (TI-{80, 83, 83+, 86, 89T, NSpire CAS}, possibly a few others) but actually use a TI-89 Titanium emulator on my Android phone. I no longer do anything remotely interesting with it, but I prefer it to the stock calculator since I know how it does order of operations, it shows fractions, it's easy to get old return values, etc. Don't tell me if the stock calculator now does all that; the TI-89 ergonomics are burned into my brain. (I was in an advanced math class which got me using a TI-80 at the age of 9)

Yes, not for its technological features but for its single-purpose-ness. If I'm working on paper, it's nice to pull out rather than a full on computer which also has all of my email on it.

I still have my Casio FX-83MS which my mother purchased for me when I started secondary school 24 years ago. It still works, it usually sits on my desk, and I use it a couple of times per month.

When I have a calculator near me, then I do prefer to use it rather than having to open the terminal, run python, import libraries etc. It is faster for simple computation.

I use a Casio. Not just calculator, but for any tool, I try to avoid using my phone. A phone is a rabbit hole. Once you pick it up, you never know what notification will interrupt your flow. Besides, for these utility apps are difficult to monetize, it's hard to find one that isn't bombarded with ads. Even if luckily you find a perfect one, the creator might lose interest and stop maintaining it next year, forcing you to change your usage habits.

I still use a high school calculator for doing pen and paper maths. Stuff like figuring out when functions change sign. I find it less distracting than a code editor

I keep my ~25 year old Ti-83 or 84 from middle and high school in my shop because I find using it while working on stuff with dirty hands much easier than my phone or tablet. I just need something which basically never needs new batteries and lets me use parentheses to group expressions and the occasional trig function. I think the current batteries are almost ten years old now.

I still use my casio fx-83gtx from time to time, if I'm doing something especially complicated. Having a physical devices feels nicer than using windows calculator or my phone. I use desmos for things where graphs would give more insight, and wolfram alpha where I need more than the specific answer, and some information around it might be useful

Yes. When accounting I use a cheap calculator to do quick sums. Easier than using a calculator on the computer desktop.

Haven't had a need for a hardware calculator since the first year in the university, even though I got to the PhD in physics. The calculations are either too hard to do by hand (at work) or too trivial and few to require anything more complex than a basic Android or Windows calculator.

Yes! I’ve held onto my TI84 from high school and find myself reaching for it far more than I ever expected.

I use a SwissMicros DM16L (a HP16C clone) because I like RPN and prefer physical buttons over a touchscreen.

Yes, I do. At my workbench, I find them much faster and more convenient than using my phone or a computer.

I actually own one, a Casio. Simple reason, I'm a ham radio operator and you need one for the exams.

I would, but one of the main keys stopped working. It is a very old solar scientific calculator and large for a calculator.

If I could open up the case without cracking it I would attempt a repair, but I know I would end up breaking it :(

Now, I mainly use bc(1).

I still have them, also a slide rule, but no, I don't use them. It is essential to have these for when the grid breaks like it currently has in Mississippi for over a week. I also have multi-decade-storage batteries for them.

Yes. In fact I even made a video about them: https://www.youtube.com/watch?v=kdbfPa1L6JQ (shameless self-plug, yes).

Absolutely!

On my desk I have an HP-28S and use it nearly every day.

In the office I have a newer HP, which isn't quite as nice to use as the 28S but still quite good.

The ergonomics of these are so far superior to using software apps that there is no comparison.

Yes. HP-11C. Who cares about the speed of the calculating device when I'm just adding or multiplying a few numbers? Physical buttons are easier to use than mousing on a screen. And it's highly portable.

I still use my dad’s old HP 15C. Form factor is good, aesthetically it’s very appealing, it feels efficient to use, I like the tactile feel of the buttons, and I like thinking of my dad when I use it.

I do. I struggle with basic math (always have) so I keep a simple calculator right next to my keyboard because it's instantly available as compared to the one in my phone or on the computer.

I like a physical calculator if I'm doing my taxes, monthly budget, or if I'm doing a lot of calculations. If I'm quickly adding something up, I use Wolfram Alpha or my phone.

Oi! You forgot adding machines. Big buttons, +/- features, auto-tax. And! Inexplicably none of the pre-installed calculators emulate them—bizarre.

And yes, I do use an adding machine, Sharp EL-1750

I use an emulated scientific calculator Android app which has all the features of a physical calculator but none of the performance issues.

If I'm at my laptop, I usually just use a IPython REPL.

Yes. Casio FX-991 es plus.

I did use for integrals, derivatives, etc, in a distant past.

Now I'm using to do simple calculations, including checking Claude code/opus math and logic.

I have an HP-12C I keep In my laptop bag, and I also have a construction calculator I use on occasion.

The most valuable is usually the printing calculator I use for totaling sums on occasion.

tl;dr: RPN - ride or die. ;)

Sometimes, for vintage reminiscing, a real HP48GX.* It got me through AP Calculus BC, SAT-I, and EE/CS. And doubled as a learning TV remote & TV-B-Gone. I also have a virtual HP48 on my phone, tablets, and computers.

In middle school, I had an HP 32SII. I remember being able to hear** either the processor clock or data line(s) of each of the 32 and 48 because one or more components acted as inadvertent audio oscillators that would make noises during computation (and during idle on the 48 because it had to keep redrawing the clock).

I've used R, MATLAB, pspice, and Mathematica in the past.

I'm a fan of Xcas and Wolfram Alpha now.

* I also have a collection of HP 48[GS]X cards, the printer, and the overhead projector adapter. In lieu of the overpriced official HP 48G to computer RS-232 interface cable, one can be easily made from a Sony CD-ROM audio cable.

** With my much younger ear pressed up to it.

Every programmer and engineer I work with has a calculator at their desk.

It's like having a second monitor, just for math, and you can take it with you. Modern technology is incredible.

I still regularly use a TI-35, and / or an old slide rule (I have three), and / or rough mental order of magnitude guesstimates.

Otherwise I use domain software for other tasks.

I still use a basic calculator once in a while when I want to get away from a screen and just work on paper.

I haven't turned on my old TI-85 in a while.

Haven't used my Casio calculator to solve real stuff in a few years, and it still works whenever I check it out at random moments to know if it still works.

Great battery, that.

wish i still had my hp48g, the emulator apps are the most used apps on my phone/ipad, they re glorified calculators*ipod by now with worse buttons.

Yes. My TI-30X has been in my backpack since I started college 17 years ago. It still works flawlessly every time I pull it out

Haven't used one since the day I finished school. I still have it though. It's like an artifact from another time...

Yes! I keep a basic Casio MS-80s handy for sanity checks and a 30-year-old CFX-9850GB Plus for when things get serious.

I keep my TI-84 at my desk and reach for it maybe once a week. Usually for money reasons though, not so much for work stuff.

I use a Casio HL-815L to manage my checkbook. I lost the ability to do this math in my head about 10 years ago. I am 77.

Does Windows Calc.exe count as well? :-))

Electrical engineer, ti89 in the desk. Also how else am I going to maintain my brick breaker dominion.

Button feedback, reduced chance of fat fingered mistype. Doesn’t tie up phone holding numbers on screen.

i still use my TI calculator for the engineering days. It's such a useful piece of hardware. I dont do any big calculations anymore but still gives you that feeling of slowing down without notifications.

A REPL of your favorite scripting language is the best calculator there is IMO.

I do. It just works, and it feels better than the on-screen versions. The Windows calculator is atrocious. Some of the emulators for iOS are good, but still feel clumsy in comparison to the real thing, especially for more than adding two short numbers.

The truth is: I like calculators, and I think almost everyone answering in the positive does too. Most people don't care about them, and see their phone as a god-given miracle, I guess, which makes calculators an expensive-ish burden.

Yep. College requires a TI-83 and I use a DM-16L for accounting homework.

My kids often use their hands, I sometimes use paper and pencil

Mines are stored, but I use the hp48 emulator regularly.

Yes, I use one all the time. I have a small collection of them, depending on the task.

As for why I use them?

- They are tactile.

- They are forgiving, pushing a button doesn't accidentally swipe to some random app or screen or slide down notifications.

- The physical calculator doesn't interrupt my work with a notification or popup.

I realize it makes me a boomer, but using modern smartphone interfaces, especially post-home button iOS, feels like interacting with a UI sitting on top of a banana peel. Buttons now require more precise and well-timed touches to activate their actions (eg: the buttons on the lock screen). I frequently find myself accidentally swiping between apps or navigating to new views.

I really wish I could go back to the old way of having a singular app be the focus, and having a home button or something I can press to switch between app contexts, without all the easily triggered and hidden gestures.

> I’ve noticed that most physical scientific and graphing calculators are easily outdone in terms of performance, capability and ease of use by the likes of Desmos and the default calculators on OS’es like the iOS, Android, and Windows.

Citation needed. They are pretty clunky, unless you have a numpad typing on them takes way longer. Graphing and fast access to mathematical functions is way worse.

I mean I do substituted my calculator with the computer, but the replacement is Python and GeoGebra, not the built in calculator. And the reason is mostly convenience of not replacing batteries. I do use the standalone calculator while the batteries are full.

I use it while learning mathacademy

HP-16C

Casio fx81

I use only the HP once in a while for old times sake.

I have Casio FX-991MS on my desk

TL;DR: school/tests/exams don't allow phones.

Here in NL - Casio FX-82NL is allowed during test/exams for middle/high school, and actually for Radio Amateur/HAM licence exam - they even hand you one of their FX-82NLs.

Other more advanced (graphing, with memory/Python/etc) are also allowed in some places, but they need to be set to exam mode that disables memory/python/etc.

I’m too used to using a ti-83+

No. Droid48 has replaced it.

no, python is all my need^_^

Yes!

"Do you still physical calculators?"

Well, no. My calculators don't bounce around so I have no reason to "still" them. /s

I have a calculator app that I use 99.9% of the time. I have a physical calculator around here somewhere. I used to use it when I'd have to tabulate physical items or when I'd been doing calculations for a long time. Short bursts on my phone are fine, but over hours is kinda troublesome.