CASIO fx-1000 Scientific Calculator -I believe this one is highly collectible
Casio calculator FX-1000F with owner's manual (nº57) – Casio 880
Casio FX-700P Handheld Electronic Calculator | National Museum of American History
Casio - fx-1000f - - Scientific calculator - Casio fx1000f - Casio.ledudu.com - Casio pocket computer, calculator, game and watch library. - RETRO CALCULATOR FX PB SF LC SL HP FA
Amazon.com : Desktop Calculator Large LCD Display 12 Digit Number Handheld Portable Pocket Basic Calculator with Big Soft Sensitive Button, Battery and Solar Powered, for Office Home School Use(OS-6M) : Office Products
Amazon.com : Large LCD Calculator, Dual Power Desktop Business, High School, UNIONE CX-950 4.7×6inch : Office Products
Vintage Casio fx-201P Scientific Calculator Vintage Tested Working | eBay
Amazon.com : Casio Power Graphic Graphing Calculator Algebra FX 1.0 PLUS : Office Products
Bohsei Model 1000 Handheld Electronic Calculator | National Museum of American History
Amazon.com : Casio SL-310SV, Sloar Powered Standard Function Calculator : Office Products
Amazon.com : Casio MS-80B Standard Function Desktop Calculator / 5 Pack : Calculators : Office Products