An arrangement of numbers on a square grid where all the numbers in each row, in each column and the numbers in the diagonals all add up to the same number is called a Miracle Magic Square. This is a mental magic masterpiece that uses a magic square theme. This trick can be performed very easily and every spectator will marvel at your amazing mathematical ability.
The magician asks a spectator to secretly select a random number from a sheet the magician displays. Next the magician writes sixteen different numbers on a grid that's printed on a piece of white cardboard. The secretly chosen number is not included in what the magician wrote but he has actually made a magic square using the spectator's number. All of the rows and columns add up to the spectator's number. All of the four corners and diagonals of four add up to the spectator's number. Even the four squares of each corner add up to the spectator's number!