Most real numbers can not be stored on a computer. One can distinguish two kinds of approaches to run real number computations. First of all one can restrict to (countable) subrings such as the integers, rationals or algebraic numbers. A second possibility is to perform approximate arithmetic with floating point numbers or their smarter derivatives intervals and balls. It is sometimes desirable to have a mixed approach. The aim of this talk will be to offer a survey of what is available, defective and desirable in SageMath for real number computations.