Eight-digit calculator features a hinged, hard cover for extra protection when stored. Large LCD clearly shows each digit to help prevent reading errors. Twin-power operation runs on solar energy with a battery backup to deliver consistent, reliable use in any environment. Handheld calculator also includes three-key independent memory, square root key, change sign key, automatic power down and more.Eight-digit calculator features a hinged, hard cover for extra protection when stored. Large LCD clearly shows each digit to help prevent reading errors. Twin-power operation runs on solar energy with a battery backup to deliver consistent, reliable use in any environment. Handheld calculator also includes three-key independent memory, square root key, change sign key, automatic power down and more.