Casio Desktop Calculator 12 Digits, Two Way Power (Solar + Battery) , Large Display, Key Rollover, Key operations are stored in a buffer, so nothing is lost even during high-speed input, All the mark-up capabilities of an adding machine for simplified cost and profit calculations, Automatic calculation of price plus tax, price less tax, discount, selling price, tax amount, discount amount, and margin amount, " % " key gives quick access to prices and profits, and also delivers add-ons, discounts, ratios and increase/decrease values.