Perfectly fitted to your right finger for easy typing. With our new “Ergonomic Step Keys” structure, your calculator matches the contours of your hand instead of requiring you to adjust for the calculator. Unique features of HEAVY DUTY calculators Extra Large Display Larger display makes more data easier to read. Durable Anti-fade keys Keys are produced by injecting plastic of two different colours. Key markings are plastic, which means they do not wear or fade with use. Key Layout and Key Cap Shape Keys are ergonomically shaped and configured to match natural finger movements. Non-slip Structure Large rubber feet on the bottom of the calculator keep it from slipping during operation. Function Command Signs A symbol (+,−,×,÷) on the display indicates the status of the operation you are currently performing. Solar & Battery Solar powered when light is sufficient, battery powered when light is insufficient. Silent Touch Keys Keys are specially designed for silent operation when compared to previous CASIO calculators to help maintain a more pleasant working environment. Three-Key Rollover Key operations are stored in a buffer, so that nothing is lost even during high-speed input.