The Casio Scientific Calculator FX 991MS is a non-programmable scientific calculator from Casio. It has 401 functions and a wide, 2‚¬Å¡¬ display which supports a 2-line display. It has 10-digit mantissa and 2-digit exponential display. The colour coded keypad allows easy differentiation between different types of keys. It also comes with a slide-on hardcase which keeps it safe against damage when you are on the move. You can solve differentiation, integration, vector, statistics, regression, matrix etc. It offers quick and easy recall of previously executed formulae for recheck and corrections.