Challenging the Students‘ Sense of Mathematics Via Decoding Problems in Chernorizec Hrabar Tournament

Under consideration is a thematic branch from the Chernorizec Hrabar (ChH) math tournament, which aims to check and develop the student’s sense of mathematics. The ChH competition papers include several types of test items related to codes. These test items require just basic math knowledge but a high level of nonstandard reasoning and a kind of synthetic mathematical abilities. The authors’ standing point is to present by examples how the idea of (de)coding evolves in competition papers for students in different ages.