A stylish home or office essential that is ideal for everyday equations & calculations. Large, 12-digit display & keys for easy viewing & clicking. Dual solar / battery power provides reliable functionality in all lighting conditions. The completely flat design allows for easy storage. Features square root, +/- switch, & percent keys help to easily find the answer to more complex calculations. Power Source(s): Battery; Solar; Display Notation: Numeric; Number of Display Digits: 12; Display Characters x Display Lines: 12 x 1.