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. 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. Handheld calculator also includes automatic tax keys, percent key, square root key, four-key independent memory, automatic power down and more. compatible with Sharp EL-377WB 10 Digit Professional Handheld Calculator, White, 1 Each (Quantity) Extra-large, fixed LCD displays crisp digits to prevent reading errors Durable keys are comfortably spaced for accurate data entry Backspace key allows fast, simple corrections for time-saving use Twin-power operation ensures consistent, reliable use in any environment Includes automatic tax keys, percent key, square root key, and four-key independent memory