The Canon MP11DX has the perfect combination of useful and sophisticated features for the busy professional. This desktop, two-color printing calculator incorporates profit margin calculation keys, which allow you to calculate the selling price or discount, based on the cost and desired profit margin. Another time saver is the tax feature. You can store a rate that you use frequently and use it often eliminating many steps of your calculation. In addition, the built-in clock and calendar allows you to view the time and date on the display or print them out.