This 12-digit professional desktop calculator with kick stand is perfect for business professionals at home or in the office. It features a large LCD display and large keys. Cost/sell/margin keys make for quick and easy profit margin calculations, simply enter two variables and the third automatically appears. Other functions include a grand total key, double zero key, backspace key, automatic tax keys, percent key, 4 key independent memory, extra-large plus key, sign change, and automatic power down. Operates on twin power (solar and battery) and automatically switches power sources in low light.