Ⅰ. Bamboo Office Calculator 12 Digit LCD Display School Special Gift Christmas Calculate Commercial Tool Battery Solar Powered Ⅱ. Features: Ⅲ. 1. The calculator design of 12 bits, the results don't round Ⅳ. 2. When operation bits over 12, error handling, reset only by pressing the ON/AC Ⅴ. 3. When inputing error, press the backspace key to delete bit by bit. Ⅵ. 4. The calculator automatically shuts down after 12 minutes of no-operation, then enters the sleep state; you can press ON/AC to awake it. Ⅶ. 5. When the operation result beyond 12 negative, negative sign does not show. Ⅷ. 6. Please avoid using it under strong light Ⅸ. Specifications: Ⅹ. Power: SOLAR Ⅺ. Dimension: about 170*82*19mm (6.69x3.22x0.75 inch) Ⅻ. Supply Battery: solar power, no need to replace the battery XIII. How to use? XIV. Please rub the LCD screen and solar panels with a soft dry cloth; store in a dry and cool place when idle. It is forbidden to place the product in water or under sun exposure XV. Package included: XVI. 1x Bamboo Electronic Calculator