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
fx-82MS-BU | SCHOOL & LAB. | Calculators | CASIO
You May Not Know: 20 Cool Features Of Casio fx-82MS Scientific Calculator! - YouTube
Casio FX-82MS 2ª Edition Scientific School And Graphic Calculator @ Best Price Online | Jumia Kenya