CASIO fx-1000 Scientific Calculator -I believe this one is highly collectible
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Casio カシオ 】 関数電卓 Casio fx-260 SOLAR II 分数と科学の電卓 文具/計算機/オフィス用品/ソーラー :10001453:AJマート - 通販 - Yahoo!ショッピング
Amazon.com : Casio FX-260 Solar Scientific Calculator School Version (Fraction Key is Not Operable) : Office Products
CASIO FX-1000 VINTAGE CALCULATOR | eBay
Casio fx-83GT CW Class Kit - Black - Science Studio
New ClassWiz. Boost your curiosity. - Casio Calculators
Amazon | Casio fx-115ESPLS2 White Advanced Scientific Calculator with Natural Display | 関数電卓 | 文房具・オフィス用品