The changes in the rules compared to the previous year are highlighted in **bold**.

- Online competition MatX (further only "competition") is a team competition in Mathematics for the students of elementary schools and gymnasiums.
- During the course of the competition the teams will solve and answer various mathematical problems. These problems are selected in a way that no specific mathematical knowledge is needed. These problems can be solved by using logical thinking.
- The competition has 6 categories: 7th grade (elementary school), 8th grade (elementary school), 9th grade (elementary school), 7th grade (gymnasium), 8th grade (gymnasium) and 9th grade (gymnasium).
- The best teams in each category will receive prizes.
- The competition will be held on Tuesday 31st December 2999. The competition will last for 90 minutes. The exact start time is chosen by the school itself.
- The entry fee for the first team from a school is 10 €, for the second team it is 9 € etc. The tenth team hence pays only 1 € and all other teams compete for free. The maximum number of teams registered by one school is 15.
- It will be possible to solve the problems in Slovak, Czech and English lenguages.
- The competition is organized by the non-profit organization P-MAT based in Slovakia. Address: Ambroseho 2, 81504 Bratislava. Company registration number (IČO): 31820832. Tax identification number (DIČ): 2021323898. This non-profit organization offers public services in education.

- A team can have at most 4 members.
- All team members must attend the same school.
- In the most common case the team consists of 4 members from the same grade (not necessarily the same class). In this case the team competes in a category related to this grade.
- In extraordinary cases, a student from a lower grade can also join a team in a higher category (e.g. you may want to create a team of three 8-graders and one gifted 7-grader). In such case, the team will be assigned to the category based on the student of the highest grade. In case of any questions about this rule, please contact us via an e-mail.
- Registration of teams to the competition as well as the supervision of teams during the course of the competition is the responsibility of a teacher.

- Teams are registered to the competition by their teacher. Registration is open since 1st March 2020.
- The maximum number of teams registered by one school is 15.
- You can register multiple teams from multiple categories from your school at the same time.
- Upon completion of the registration, the teacher will receive log-in information for all teams (team IDs and passwords) and payment instructions.
- By paying the competition fee, the teacher and the school agree to the rules of the competition.
- You can check your payment status in the Teams section.

- The competition will be held on Tuesday 31st December 2999. The competition will last for 90 minutes. The schools will be able to adjust the exact start time within certain boundaries by themselves. The start time will be the same for all teams from the same school. The school will choose the exact time based on an e-mail we will send approximately one week before the competition starts. In case the school will not choose their own starting time, it will be automatically set to 9 AM.
- The competition consists of 35 problems. The aim of each team is to obtain as many points as possible (see the Points section). The points are awarded for correctly solved mathematical problems.
- The problems are the same for all categories. The final ranking will be divided into respective categories.
- It is requested that the teams are under the supervision of a teacher during the course of the competition.
- The teams compete for themselves. Therefore any cooperation among the teams or between a team and a different person (e.g. teacher) is strictly forbidden. The teacher may help only to submit the answers, if necessary.
- During the course of the competition it is allowed to use calculators, tables, Excel or anything that can help with the problems. However, the problems are selected in such a way that the teams have to use mostly logical thinking.
- In each moment of the competition, the team solves exactly one problem. If the team thinks they have a correct answer, they can submit it. The answers are always numbers, words or multiple-choice. If necessary, the format of the answer is specified within each problem.
- Team has exactly one attempt to correctly answer a problem.
- After the team answers a problem, the next problem is immediately displayed. The team will not immediately know, whether their solution was correct. This information will be made public only after the competition ends - together with the final ranking and model solutions of the problems.
- If the team can't solve a problem, they may choose to skip it. This can be done at most 5 times. Be aware that skipping a problem may have a different effect on points than submitting a wrong answer! For details see the Points section.
- It is not possible to return to any of the previous problems. This includes skipped problems.
- It is necessary to get familiar with the pointing system, because even a team that answered only 10 problems (but correctly) may receive more points than a team that has seen all 35 problems, but answered incorrectly in a rush.

- A team with the highest number of points within a given category wins the competition. In case that two or more teams have an equal number of points, the higher number of maximally-awarded points for individual problems decides (the more, the better). In case this criterion does not determine the winner, the time of submission of the last correctly solved problem decides (the sooner, the better).
- The rest of the ranking is determined in the same manner.
- The team is awarded 0 points for an incorrectly solved or a skipped problem. The team receives 3 points for a correctly solved problem. However, in case the team has correctly solved also the previous problem, they will receive 1 bonus point (so 4 points in total). In case the team has correctly solved
*n*previous consecutive problems correctly, they will receive*n*bonus points (so 3+*n*points in total). - Incorrectly solved problem breaks this sequence of bonus points. Thus, the team receives only 3 points for a correct answer right after an incorrect answer.
- A skipped problem, however, doesn't break this sequence of bonus points. It is simply ignored. Each team has at most 5 skips available, so it is necessary to think before skipping a problem. It is not possible to return to a skipped problem afterwards.
- In each moment of the competition, the team sees the remaining number of skips.

- The team has incorrectly answered the problems no. 2, 3, 6 and 7. Therefore, they receive only 3 points for the correctly solved problems no. 4 and no. 8.

- In this case, the team has skipped the problem no. 7. Therefore, they don't lose the bonus points for a correctly answered problem no. 8 and receive 6 points for it.

- The team has skipped the problem no. 2, but they submitted incorrect answer for the problem no. 3 afterwards. Therefore they received only 3 points for the correctly solved problem no. 4. The team has also skipped the problems no. 7 and no. 8 and they therefore don't lose the bonus points for the correctly answered problem no. 9.

- Right after the team finishes the competition, we will display the number of points awarded.
- We will announce the unofficial results and upload the model solutions of the problems approximately 10 minutes after the last team finishes the competition.
- No later than 24 hours after the end of the competition we will announce the official results. They will be available in the results tab.
- We will send prizes and diplomas to the best teams in each category.