I clicked hoping this would be about how old graphing calculators are generally better math companions than a phone.

The best way to do math on my phone I know of is the HP Prime emulator.

GraphNCalc83 is awesome [0].

[0] https://apps.apple.com/us/app/graphncalc83/id744882019

My personal favorite is iHP48 (previously I used m48+ before it died) running an HP 48GX with metakernal installed as I used through college. Still just so intuitive and fast to me.

I was pretty delighted to realize I could now delete the lame Calculator.app from my iPhone and replace it with something of my choice. For now I've settled on NumWorks, which is apparently an emulator of a modern upstart physical graphing calc that has made some inroads into schools. And of course, you can make a Control Center button to launch an app, so that's what I did.

Honestly, the main beef I have with Calculator.app is that on a screen this big, I ought to be able to see several previous calculations and scroll up if needed. I don't want an exact replica of a 1990s 4-function calculator like the default is (ok, it has more digits and the ability to paste, but besides that, adds almost nothing).

I run a TI 83+ emulator on my Android phone when I don't have my physical calculator at hand. Same concept, just learned a different brand of calculators.