Náboj is an international mathematical competition designed for teams of five high-school students that represent their schools. The competition lasts 120 minutes during which the teams are trying to solve as many given problems as possible.

At the beginning of the competition each team receives six problems. As soon as the team correctly solves any of the problems, it receives a new one. The solutions of the problems are usually numerical. The team that solves most problems correctly in the given time limit wins.

Participation in the competition is free of charges.

A more detailed description of the competition can be found in the section rules.

About the Problems

Difficulty of the problems is appropriate both for students inexperienced in mathematical competitions and for students who have already succeeded in Mathematical Olympiad. This is achieved by arranging the problems in order of their perceived difficulty. Problems in Náboj differ considerably from the routine school exercises which usually require only direct application of a given method: the Náboj problems require certain amount of inventiveness and ingenuity. Success in the competition does not depend on the individual abilities of the team members only but also on their efficient cooperation. Apart from enhancing imagination and logical reasoning our goal is to attract people to the endless beauty hidden in mathematics.

In 2011, the professional quality of the problems was guaranteed by the Department of Mathematical Analysis, Charles University in Prague.

Problems from previous Náboj competitions can be found in the archive.

Competition Sites

Náboj takes place simultaneously in Prague, Opava, Bratislava, Košice, Edinburgh, Passau, Linz, Warsaw, Krakow, Wroclaw, Gdynia, Budapest, and Veszprém. In each of these sites there is a local ranking of individual teams. Students are also able to compare their performance in the national and international ranking.


Teams compete in two categories, Juniors and Seniors. Students participating in Junior category must be in S4 or earlier year. The Senior category is open to any team consisting of secondary school students.


The best teams will receive certificates and prizes according to their placement. Previous years' prizes included first-class mathematical literature used worldwide for preparation for mathematical competitions, electronics, or board games. This year we have prepared even more attractive prizes.


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