The Big Red Calculator is capable of displaying very large numbers like "Trillions", or calculating the National Debt and the Federal Budget Deficit. For business, office and home use. Large digits allow easy viewing and large sure-feel buttons make digit entry reliable. Dual power allows for use in varied lighting conditions. Includes illustrated step-by-step manual with sample calculations.Features include 16-digit large LED display capable of showing "trillions", with Tax, Mark Up, 112 Step Check, Auto Replay and Grand Total functions, solar/battery power, large sure-feel buttons, bold red color, easy-to-read instructions, CE/RoHS compliant.