The aim of this paper is to show how to attract the attention of high school students during teaching of non-popular chapters in mathematics by choosing the appropriate motivational example. Great emphasis is placed on the choice of reasonable examples and in order to ensure that the task is brought from real life and that students are curious about the solution itself. The selected themes for this paper are related to concepts of sequences, series and similar triangles. The biggest problem for students is usually translation of the worded task in relation to a real situation into a correct mathematical language and also selection of a method, which will prove effective and appropriate for solution of the problem. As an example, we are discussing upwind sailing of a yacht in the open sea as a possible suitable motivational example. Another aspect of the selection of tasks, which can also be emphasized, is the effort to attract the student attention and, above all, to offer students some new knowledge and experience related to unknown problematic during solving tasks.