This article aims to explain and justify the use of Feynmann diagrams as a computational tool in physics. The integrals discussed may be seen as a toybox version of the real physical case. It starts out with the basic one-dimensional Gaussian integral and then proceeds with examples of multidimensional cases. Correlators and their solutions through generating functions and Wick's theorem are shown, as well as some examples of how to relate the computations to diagrams and the corresponding rules for these diagrams.