I am asking about how to use Casio calculator. Introduction to use: In the matrix mode of the calculator, fx-991cn Then use the sto button on the keyboard. If you need to copy mata, matb, matc or matd, you can select (-), ".,,", x-1 or sin key accordingly to copy the matrix variable.

CASIO fx-991CN X is a widely praised scientific calculator. Needless to say, its performance and functions have helped countless users solve computing problems.

Read more instructions and become familiar with how to use it.