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-82MS 2nd Edition (14-413121) | TIA Mobiteli
Casio FX-82MS - Wikidata
FX-82Solar II | Technical & scientific calculator | School and graphic calculators | Products | CASIO