Casio Scientific Calculator: owned since 1999, used through high school years 8 - 12, a degree in accounting, my current workhorse in my underwriting job. Maybe my favourite possession. : r/BuyItForLife
Casio FX-991ES Plus-2nd Edition Scientific Calculator With Bill Original | eBay
The World of Possibilities: Casio Classwiz FX-991 CW Scientific Calculator | by Amrish Tyagi | Casioindiashop | Medium