Casio FX-991AR X 12 Digit Scientific Calculator Black/White Number of Functions: 542 Display expression same as textbook. 10 + 2 digits10-digit mantissa + 2-digit exponential display. High-resolution screen provides beautiful looking graphs every time. Quick and easy recall of previously executed formulas for editing and re-execution. Designed and engineered for easy operation. Viewing and editing of input data in list format, showing data groups (x-data, y-data, frequency) and surrounding data.