With around 6000 participants from Germany, Europe and the rest of the world, the MATH+ Advent Calendar (also known as the Mathekalender) is an important part of the outreach activities of the Berlin Mathematics Research Centre MATH+ and 4TU+.AMI. This annual, digital advent calendar contains 24 challenging math puzzles, primarily aimed at curious high school students, that are published online daily between 1 and 24 December.
The first edition of the calendar, in German, ran in 2004. Six years later, 4TU+.AMI joined the initiative, originally by running a Dutch version of the calendar in parallel to the German one, later -when the language of the calendar changed from German to English- by contributing some of the puzzles to the calender hosted by MATH+. For many years, the driving force behind the calendar in the Netherlands was Gerhard Woeginger. Gerhard, who sadly passed away in 2022, kept contributing many beautiful puzzles even after his move from TU/e to RTWH Aachen in 2016. Since 2022, the coordination of the 4TU+.AMI contribution to the calendar is done by Pim van ‘t Hof (UT).
The vast majority of the partipants is from Germany, but people from more than 70 countries participate in the competition. After Germany, the Netherlands is the country with the highest number of participants. After a national promotional campaign last year, where 4TU+.AMI sent out posters advertising the calendar to all high schools in the Netherlands, the number of Dutch participants increased by 64% from 254 in 2024 to 417 in 2025.
Award ceremony in Berlin
Participants in the MATH+ Advent Calendar compete for several prizes that are awarded by MATH+. Apart from that, the top-scoring pupil from a Dutch high school receives a prize sponsored by 4TU+.AMI. (More on this very soon!) The prizes awarded by MATH+ are handed out during the annual festive award ceremony at the Max Kade Auditorium of the Free University of Berlin, together with the prizes that are handed out to the winners of the “Mathe-im-Advent” initiative. Just like the MATH+ Advent Calendar, Mathe-im-Advent is a digital mathematics competition that runs in December in the form of an advent calendar, the difference being that Mathe-im-Advent is aimed at younger pupils and has over 180.000 (!) participants each year. On behalf of 4TU+.AMI, Pim van ‘t Hof attended this year’s award ceremony in Berlin, where he met with the project team of the MATH+ Advent Calendar.
Puzzles contributed by 4TU+.AMI
As mentioned before, the puzzles for the MATH+ Advent Calendar are created by researchers from MATH+ and 4TU+.AMI. For the 2025 edition of the calendar, 11 of the 24 puzzles that were selected for the MATH+ Advent Calendar were submitted through 4TU+.AMI by 9 different authors (Marko Boon, Hajo Broersma, Mar Curcó Iranzo, Eva Deinum, Pim van ‘t Hof, Stella Kapodistria, Lucas van Kreveld, Matthew Maat, and Mehmet Akif Yildiz).
One of the two puzzles submitted by Matthew Maat (UT), entitled “The Road from Bethlehem”, was voted the second most popular puzzle in the calendar, losing out to the most popular puzzle by a single vote. (Matthew Maat also finished second in the best challenge vote in 2023 with his puzzle “The Triangle of Al-Bermuda”. In the 2024 edition of the calendar, one of the 4TU+.AMI contributions -“Cutting Christmas Cookies”, submitted by Pim van ‘t Hof and Stefano Piceghello (both UT)- actually won the best challenge vote.)
4TU+.AMI would like to thank everyone who submitted a puzzle for the 2025 edition of the MATH+ Advent Calendar. If you would like to contribute to the upcoming edition of the calendar, please visit this page for more information.
