Registration has just opened for the Junior Mental Calculation World Championship 2026!
Since 2008 this international championship in mental calculation has taken place. Caroline Merkel and the team welcome all young people around the globe aged up to 19 to participate, challenge themselves, and develop their skills.
I attended the last 6 events as an official trainer, and I’ll be there again this year! Each event was a friendly and enjoyable weekend with 50–100 participants from many countries, including Panama, South Africa and Turkmenistan.
The event will be held on the 05–07 September 2026 in Bielefeld (Germany). Here is a summary of the official schedule:
- Fri 04 September: most people arrive
- Sat 05 September: training workshops (with international experts in calculation) and social events
- Sun 06 September: training workshops (with international experts in calculation) and hectoc challenge
- Mon 07 September: JMCWC competition and award ceremony
- Tue 08 September: remaining people leave
Applications to Join
Please visit its official website for full details and future updates about the competition. Applications are accepted until 30 April 2026—you can read here the instructions for how to apply. Places are limited!
Note: please do not contact me (Daniel Timms) about applications—please follow the instructions above and speak with Caroline Merkel 🙂 Any information from the official website supersedes any information on this page.
Event Details & Preparation
The aim of the event is to share knowledge and methods with the participants. To facilitate this, the event includes free training the days before to prepare the students for the competition. The training will be coordinated by a small team of established international experts in mental calculation such as George Lane, Freddis Reyes, Elke Kuge, Martin Drees, Daniel Timms and others.
Entrants will compete in their age category:
- under 12 years
- under 15 years
- under 20 years
The competition will be a 2-hour written exam, where participants must not write down anything except the answers! Here are some resources to help students prepare:
- Specific resources for JMCWC 2025, including a simulator of the 2025 paper (although without the Surprise tasks). If there are minor updates for JMCWC 2026, we’ll tell registered participants about it.
- Official JMCWC website page that lists the types of question that appear in the event.
- Pegasus Excel software that is used for creating the competition questions (note: also includes many categories not in the JMCWC).
- Resources page for mental calculation training in general.
If you’re interested in mental calculation and born after 2006-Sep-07, or you’re a parent/trainer of someone who is, I hope to see you there in Germany this September!
Photo credit: Andreas Mohn Foundation, who have kindly sponsored this event for many years.