10-digit calculator features an extra-large LCD that displays crisp, clear digits to prevent reading errors. Durable keys are appropriately spaced for fast, accurate data entry. Cost-sell-margin keys simplify profit margin calculations by allowing you to enter two variables and automatically receive the third variable. Backspace key allows you to make quick, single-digit corrections for time-saving use. Twin-power operation runs on solar energy with a battery backup to provide consistent, reliable performance in any environment. Desktop calculator also includes currency conversion functions, automatic tax keys, percent key, backspace key, four-key independent memory, automatic power down and more.