This 12-digit LCD display has 5/4 up/down rounding, four-key memory, change sign, auto constant, grand total, GPM, right shift, square root, percent, percent add-on/discount, variable decimal and auto power off features. Cost/sell/margin allows two variables to be entered and a third appears. New check and correct key allows user to check and correct up to 99 previous entries (Automatic replay feature). Solar power with battery backup and automatic power down feature.