Casio FX82 calculator I bought in 1982 at the age of 15. Used it throughout school, my apprenticeship and work as a draughtsman. Don't use it much now but it still works
Casio Enterprises Scientific Calculator, Each - Model FX-260SOLAR
Casio® Advanced Display Scientific Calculator - Sam's Club
Casio - fx-82 Solar - - Scientific calculator - Casio fx82 Solar - Casio.ledudu.com - Casio pocket computer, calculator, game and watch library. - RETRO CALCULATOR FX PB SF LC SL HP FA