  Numerical simulations are playing an increasingly important role in modern
science. In this work it is suggested to use a numerical study of the famous
perihelion motion of the planet Mercury (one of the prime observables
supporting Einsteins General Relativity) as a test case to teach numerical
simulations to high school students. The paper includes details about the
development of the code as well as a discussion of the visualization of the
results. In addition a method is discussed that allows one to estimate the size
of the effect as well as the uncertainty of the approach a priori. At the same
time this enables the students to double check the results found numerically.
The course is structured into a basic block and two further refinements which
aim at more advanced students.
