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-85ES Plus 2nd edition | Technical & scientific calculator | School and graphic calculators | Products | CASIO
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Bruchrechnen II mit Casio fx-82MS - YouTube
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