This creates a 500 x 500 matrix of random numbers. The semicolon at the end tells Mathematica not to print the matrix.
On most computers it takes Mathematica only a second or so to compute all the eigenvalues of the matrix and plot them.
Mathematica can handle numbers of any size.
This works out a numerical 100-digit approximation to pi.
This asks Mathematica to factor a polynomial.
Mathematica calls on sophisticated algorithms to simplify formulas.
Mathematica takes only a few seconds to work out how many ways a billion can be partitioned into sums--a frontier number theory calculation.