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 DE Plus Refresh - Schulrechner - DynaTech
fx-82ES PLUS WE | SCHOOL & LAB. | Calculators | CASIO
Casio FX-82 ES Plus Scientific Calculator - FAST CLICK ONLINE