We are extremely sorry that the Náboj competition could not take place on Friday 13th March 2020 due to the COVID-19 outbreak. The international team has, therefore, made the decision to hold it online on 11th December instead. We hope to have Náboj 2021 in person again.

If you have any questions, please contact us via the email address info-gb@math.naboj.org.


Náboj Online is an online competition replacing Náboj 2020, taking place on 11th December 2020 virtually.

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.

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


Teams compete in three categories, Juniors, Seniors and Open. Students participating in Junior category must be in S5 or earlier year (preferably from S3 to S5). The Senior category is open to any team consisting of secondary school students (preferably S5 and S6) and students who had this status in March 2020. Anybody can compete in the Open category.


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.


  • Registration starts
    16th November 2020 (12:00)
  • Second round of registration
    27th November 2020
  • Registration ends
    8th December 2020
  • Competition day
    11th December 2020

How to register

To register please fill in the registration form.

  • UK Online - Juniors
    148 spots remaining
  • UK Online - Seniors
    132 spots remaining
List of registered teams…