The HP BC220 calculator is a versatile and efficient tool designed to meet a range of calculation needs with ease. Featuring a 12-digit LCD display, it offers clear visibility for even the most detailed calculations. The calculator is powered by both solar energy and a backup LR1130 battery, ensuring reliable operation whether in bright environments or low-light conditions. It includes a variety of functions tailored for business and financial use, such as a tax function for quick and accurate tax calculations and a CSM (Cost/Sell/Margin) function that simplifies pricing and margin calculations. The key allows for easy adjustment of number signs, while the % key facilitates straightforward percentage calculations. Additional features include a Grand Total function for summing up multiple entries, a Clear Last Digit function for correcting entry errors, and a Decimal Place Selector to adjust precision according to needs. The Rounding Selector ensures results can be rounded according to specific requirements, and the Profit/Tax Selector allows for easy switching between profit and tax calculations. Overall, the HP BC220 combines practical functionality with user-friendly design, making it an essential tool for both professional and everyday calculations.