Welcome friends again to our website. In this article I will describe how to calculate matrix and determinate easily by using your scientific calculator. I will describe you the process used in CASIO fx-991ES calculator. MATRIX CALCULATION STEP-1: Press ON to switch ON your calculator. STEP-2: Press MODE and choose MATRIX. That means you have to press 6 to select MATRIX mode. STEP-3: Remember you can calculate up to three matrixes. You can calculate above this by using the result of three matrixes and carry out other mathematical operation by entering new data to the existing matrixes. STEP-4: After that you have to insert the elements of the matrixes. So press 1 to enter the elements of matrix A. STEP-5: Then choose how many row and column matrix you have. Suppose you want to calculate for a (3 X 3) matrix then press 1 or any other number according to your need. STEP-6: Input your data. To input your data type the value of the first row and first column i.e. A 11 and press = to e...