Casio Scientific Calculator: owned since 1999, used through high school years 8 - 12, a degree in accounting, my current workhorse in my underwriting job. Maybe my favourite possession. : r/BuyItForLife
Virtual Museum of Calculators
Hardware Database | Page 18 | IT History Society
Casio FX-300SA Scientific Solar and Battery Two Way Power Calculator TESTED | eBay
Changing An AAA battery On A Casio Calculator fx-83GTPLUS - YouTube