Work smarter with both solar and battery power; enjoy environmentally-friendly solar power that helps extend the battery life. Work with confidence with the easy-to-read 2-line, 10 digit LCD display. Great for the home; easily calculates measurements from home improvement to math problems. Easily power through advanced calculations such as statistics and performing complex conversions. Power Source(s): Battery; Solar; Display Notation: Engineering; Numeric; Number of Display Digits: N/A; Display Characters x Display Lines: 10 x 2.