Casio - FX-82MS. I bought it in high school, used it in University and now on my 4th year as a Professional Accountant. Haven't changed the battery once. : r/BuyItForLife
Bestand:Casio fx-82MS.jpg - Wikipedia
Casio FX-82MS 2nd Edition Calculator – The School Box
Buy Casio Scientific Calculator FX-82MS-2 For Engineering Students Online at Best Price|CasioIndiashop.com