Real Numbers
Real numbers are difficult to represent on a computer. The only way you can represent a real number is by representing the operations it would take to get there.
For instance, to represent <math>\pi</math>, you would use the string "pi"
. <math>\sqrt{2}</math> would be "sqrt(2)"
.
Using these numbers is difficult, and would rely on an algorithm to simplify the expression. This is the territory of applications like Mathematica.
Oftentimes, you don't really need real numbers. You can get your work done with floats or rationals.