In this paper we discuss a number of topics which are usually considered as a part of informatics education and we show how they can enhance substantially mathematics education. The presented problems may be used as a bridge between both school subjects which can integrate them and help to better understand mathematics and informatics and the relations between both disciplines. The informatics topics discussed here belong to discrete mathematics which plays an important role in the development of efficient computer algorithms. Some of these mathematical topics are already included in some informatics curricula, however they are still absent in mathematics education. One may expect some changes when, according to the model for ICT development, school informatics and school mathematics will reach the fourth stage (ICT specialization).