Casio DF-120MS Electronic Desktop Calculator with 12-digit Extra Large Display Casio Df-120ms Electronic Desktop Calculator with 12-digit Extra Large Display Automatic calculation of price plus tax, price less tax, discount, selling price, tax amount, discount amount, and margin amount. Calculate the cost, selling price, or margin of profit on an item, given the other two values. Solar powered when light is sufficient, battery powered when light is insufficient. A symbol (+, -, , ) on the display indicates the status of operation you are currently performing.