My dad's Casio fx-570 Scientific Calculator from more than 30 years ago, I still use it, the buttons are so tactile and satisfying to press : r/BuyItForLife
A Bossa é... Calculadoras Casio Fx 21 e FX110 1977 e Casio FX 31 1978 - YouTube
Casio - fx-21 - - Vintage calculator - Casio fx21 - Casio.ledudu.com - Casio pocket computer, calculator, game and watch library. - RETRO CALCULATOR FX PB SF LC SL HP FA