Thermal Printing Calculator with 12-digit display prints 8 lines per second quietly in black. Functions include four-key memory, mark stamp, markup/markdown, average, 00 key, repeat addition/subtraction, ADD mode, input correction key, item count and average, date and time display and set, preset text printing, decimal system, constant calculation, total and grand total, addition/subtraction by group, round off/cut off and repeat printing function. AC with battery backup.