Heavy-duty printing calculator with punctuation features a 12-digit fluorescent display. Quiet ribbon printer prints positive numbers in black, negative numbers in red, at a quick 4.3 lines per second. Includes floating or fixed decimal, add and constant modes, item count, printer and nonprint modes, and round up/down selector. Adds grand total of several calculations such as total prices x units on invoice. Markup key includes cost/sell/margin, and also performs markups, percent change and automatic add-on/discount. Calculator also includes convenient average and currency conversion functions, new time calculation and clock/calendar functions.