Two-color printing calculator delivers a valuable combination of useful & sophisticated features for the busy professional. Profit margin calculation keys allow you to calculate the selling price or discount, based on the cost & desired profit margin. Built-in clock & calendar allow you to view the time & date on the display or print them out. Double-check function helps minimize errors for more accurate calculations. Backspace button allows you to quickly correct minor mistakes for time-saving operation. Printing calculator also includes currency conversion, tax calculation, business calculation, sign change, grand total, memory function & more.