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 FX-82 Solar ab 24,24 € | Preisvergleich bei idealo.de
Casio FX-82DE PLUS ab 41,93 € günstig im Preisvergleich kaufen
CASIO FX-82 SCIENTIFIC ELECTRONIC CALCULATOR MADE IN JAPAN | eBay