[. . . ] CITIZEN model CDC-80/CDC-100 is a dual-powered (high power solar + back-up battery) calculator operative under any lighting conditions. [. . . ] [ CE / C ] : Power on / Clear entry / Clear key [M+] : Memory plus key [M­] : Memory minus key [MRC] : Memory recall key / Memory clear key [MU] : Price mark-up / down key [+/­] : ± Sign change key [RATE] : Tax rate setting key RECALL [ -TAX ] : Price without tax key / To recall tax rate when pressing [RATE] and [­TAX] keys [ + TAX ] : Price with tax key / To store tax rate when pressing [RATE] and [+TAX] keys Before performing each calculation, press the [CE/C] key two times. [ CE / C ] : An / Eingabe löschen / Löschen Taste [M+] : Speicher Plus taste [M­] : Speicher Minus taste [MRC] : Speicher Abruf taste / Speicher Löschen taste [MU] : Preisangabe-oben / unten Taste [+ / ­] : ±Vorzeicheneingabetaste [RATE] : Steuerraten-Einstellungstaste The symbol in this information sheet means that used batteries should not be mixed with general household waste. For proper treatment, recovery and recycling of used batteries, please take them to applicable collection points. For more information about collection and recycling of batteries, please contact your local municipality, your waste disposal service or the point of sale where you purchased the items. [. . . ] If you wish to discard used batteries, please contact your local authorities or dealer and ask for the correct method of disposal. [. . . ]