When one uses Google (and many people do this!), the result of the query is a list of sites that have something to do with the item one is looking for. The specific sites are always more or less on the top, so it is not necessary to have a look on hundreds of sites to read something relevant and informative. How can Google manage this? How does Google come to the suggested list? This article is primarily written for teachers and lecturers who want to share the idea of PageRank with students without having complications arising from "concepts of higher mathematics" like eigenvectors or eigenvalues. The basis is a special limit theorem (concerning Markov chains) which can be used unproved in school in order to come to interesting and elementary applications of mathematics. This example also provides a very good chance for cross-linking several mathematical fields: stochastics (probabilities, etc.), linear algebra (vectors, matrices, etc.) and analysis (limits, etc.). Another focus of this contribution is to make more visible the use of mathematics in modern society. This seems to be necessary because mathematics disappears more and more from societal perception in spite of the fact that its role rises in importance (but in most cases hidden) in our lives, it is surely a so-called key-technology.