Casio fx-991MS is a non-Programmable scientific calculator with 401 functions. The 2nd edition of the calculator comes in sleek and attractive design. Calculator has dot-matrix display for easy viewing and entering of long algebraic functions and equations. it can solve Trigonometrical, Statistical, Integral, Differential, Matrix, Vector calculations and many more... Calculator is made with wear resistance printing and has drop resistant body. This is powered by Solar & Battery both: Solar powered when light is sufficient, battery powered when light is insufficient. • Number of Functions : 401 401 Functions for easy and fast Calculations for all your mathematical and engineering problems • Trigonometrical Calculations Calculator can perform all trigonometrical and hyperbolic functions. • Statistical & Regression Calculations Calculator can easily perform statistics, regressions and distribution problems. • Matrix & Vector Calculation Solve up to 3 by 3 matrix and 3-dimensional Vector problems • Multiple Mode Single Key to change mode for Matrix, Statistics, Regression calculation etc. • SHIFT/Alpha keys for easy operation Some functions are written in Yellow and Red colors. Use Shift key to execute yellow colored functions and Alpha key for red colored functions.