Took two models of calculators with different capabilities to an exam. Plus two backups, in case the batteries died. Should have spent more time studying.
The HP-12c isn’t made as well as it used to be. Not looking forward to the day my old one is unusable.
Find and load the 12C app for your smartphone.
https://apps.apple.com/us/app/hp-12c-financial-calculator/id503641946
https://play.google.com/store/apps/details?id=com.hp.hp12cpt&hl=en_US&gl=US
In the grand scheme of things, the software is dirt cheap.