The solar energy and battery backup power supply make the desktop calculator work in low light conditions (excluding AA batteries). Basic calculator - add, subtract, multiply, divide, backspace,% and μ。 The large and sensitive keys are used for simple calculation, and are very suitable for office, primary school, market or home use. Without battery power, it may be difficult to read the screen in weak light. Please insert AA battery for continuous and accurate use. 7" L x 4" W