Up to Catalina, macOS used to have the overpowered Emacs calculator[0] preinstalled. Default keybinding to activate it in Emacs is C-x * *. I especially like how it uses RPN but also has an algebraic mode, so one can use whichever is more convenient. There's several other features that I use quite often, such as

- symbolic differentiation/integration

- conversion between units

- solving equations

- working with matrices

- rewrite systems

[0] https://www.gnu.org/software/emacs/manual/html_mono/calc.htm...

Well "bc" is still included with macOS. "bc -l" to start it in a useful mode. It's slightly quirky, but very powerful.

For example, "4*a(1)" to calculate pi.

I don’t really understand how you could read the parent comment and then suggest bc as a reasonable equivalent. For one thing I find interacting with bc to not be so interactive as gnu calc—you have to type one line at a time and it is hard to see intermediate results or make modifications. For a second thing, I don’t think bc includes:

- differentiation

- symbolic/numeric integration

- equation solving/manipulation

- unit conversion

- graphing

- vectors and matrices

- functional array operations like map/reduce

- statistical operations

- a detailed manual

Personally my main use of bc is:

  ... | paste -s -d+ | bc

I often just:

    $ python
    from math import *

When you have a hammer...

And dc (the original desk calculator) if you want RPN. I pretty much always have a terminal window with dc running for quick math. It's good for doing base conversions too.

how do you use this function? I am aware that Emacs keybinding (C-n, C-p, C-M-f) can be used in macOS' text inputs, but I somehow cannot trigger C-x to work

This keybinding is meant to be used inside Emacs.

I see...

I get your previous comment wrong then

I get almost all of my calculator needs on the mac via spotlight. cmd-space and then type whatever I need to calculate. The only thing I don't get that I'd like is the ability to do things like "34 days from today" or "days since 15 Feb 2019"

Soulver does that, from memory, and has an Alfred integration. Agreed, useful.

I'm also usually happy with these kind of tools that alloy you to do quick one liners (even google search itself can do a lot!). But sometimes I need multiple expressions. Keeping track of what I wrote already, some variables perhaps etc

Spotlight is sadly really annoying to do math in these days, since it'll spin up multiple cores trying to do useless work :/

I came to the comments to shill for Numi, which is my favorite app for quick calculations. (I don't personally understand why tiled number buttons would ever be desirable for a non-touchscreen GUI app—I much prefer typing equations in.) And I love Numi's variables which you can update and automatically propagate the changes through downstream calculations.

I came to the comments to shill for http://calca.io . For the most part has just worked and have used it in training videos, client emails, rough math sketches, etc. And the output is just markdown-formatted plaintext so you can still use it for reading purposes without the app.

From their website

> Functions can also be inverted so that you can solve for their parameters. Note how we were able to use the one equation for Fahrenheit temperatures f to calculate a Celsius temperature c.

This looks really cool. Thanks for the recommendation

Same here - my co-founder suggested that I use Numi one day, and I haven't looked back since.

Numi is cool. Use it mostly when with teams and I kept my personal that I started with -- Soulver[1] -- another interesting calculator.

1. https://soulver.com

you made numi? that things is awesome! for that kind of thing, I use Calca [1] but I admit, I have numi on my mac just because I think it's adorable. I also have the alfred plugin but it's disabled cause i dont think i figured out how to use it well on alfred.

[1] http://calca.io/

Oh I definitely didn't! Apologies if my wording implied so, I've edited it to make it clearer.

I just made the open source knock-off, as I use linux as well and wanted it on there too.

So far, I've always used MathPad for these kind of things (not the MathPad currently in the App Store, but the one written by Mark Widholm). That's an ancient application: first version was 1993, the latest version (3.0.4) dates from 2012, but it still runs on Catalina. It doesn't have the "English-ish" features of numi, but for simple, sequential calculations, it looks very similar. Apart from that, it can read files, plot in 2D and 3D, and read files.

But I'm definitely going to take a look of the two you mentioned.

Thanks for the Numi clone, I can start converting all my linux buddies!

Thanks for the recommendations! How do they compare to Soulver?

Oh my, I've been looking for that for years, and could never find it. I must have used it over 10 years ago.

To my knowledge Soulver was the first one to apply this concept, but I haven't used it in so many years I wouldn't know how it compares to Numi, although it does seem to have more features.