What happened in Bielefeld
The Junior Mental Calculation World Championship publishes its full results tables, and Scheepers's name runs through them. At the 2023 edition, held in Bielefeld from 30 September to 2 October, he competed in Junior 2, the Under-15 division, and finished third with 2,336 points. The organisers' write-up called that division the most competitive category of the year, and recorded the streak in a single line: it was his fourth consecutive medal at the championship.
That figure is the hardest fact in his record, and it comes from the competition's own results page rather than from any press release. The 2023 field numbered 70 competitors from 13 countries, among them Algeria, Bosnia and Herzegovina, Bulgaria, the Czech Republic, Germany, Hungary, India, Japan, Pakistan, Serbia, South Africa, the United Arab Emirates and the United Kingdom. South Africa is not a regular presence on the calculating circuit, which makes a run of four medals from one South African competitor conspicuous.
2025: a podium in a higher age group
The championship returned to Bielefeld from 4 to 6 October 2025, organised by Caroline Merkel. Around 80 competitors from 15 countries qualified and attended: Algeria, Bulgaria, the Czech Republic, Egypt, Germany, Hungary, India, Japan, Mexico, Panama, Qatar, Serbia, South Africa, Turkmenistan and the United Arab Emirates. Scheepers, by then in the Senior class for Under-20s, placed third with 2,663 points. The organisers noted that he had improved his score by more than 200 points.
The championship divides entrants into three age bands, Junior 1 for Under-12s, Junior 2 for Under-15s and Senior for Under-20s, so a competitor who keeps medalling is not facing the same rivals from one year to the next. Scheepers's two documented podiums, in 2023 and 2025, sit in different divisions and were won against different fields.
What the championship actually asks
The main event is a two-hour paper covering a spread of mental arithmetic categories. The organisers list addition, finding square roots and calculating days of the week among them, the last of these a calendar task in which a competitor is given a date and has to name the weekday it falls on. Scores run into the thousands of points, which is why the gap between Scheepers's 2,336 in 2023 and his 2,663 in 2025 reads as a substantial improvement rather than a rounding error.
A separate Hectoc competition ran alongside the main paper in 2025 and drew 114 participants. Hectoc hands a competitor a string of six digits from one to nine and asks for arithmetic that turns them into 100. Whether Scheepers entered that side event is not stated in the results summary used here.
What is documented, and what is not
The published tables record placings and point totals. They do not record biography. Scheepers's date of birth, home city, school and training routine are not stated anywhere in the sources used for this page, and no interview with him appears among them. His age can only be inferred from the divisions he entered: Under-15 in 2023, Under-20 in 2025.
The 2024 edition of the championship also took place and its results were published, but his placing that year is not stated in the material checked here. Nothing in these sources describes what he intends to do next, whether he still competes, or what he studies.
How rare this is
Competitive mental calculation is a small world. The 2025 junior championship drew roughly 80 people from 15 countries, and the 2023 edition 70 from 13. A single podium finish in a field that size is already unusual, because the people who reach it have generally trained for years on specific families of problems: multi-digit addition under time pressure, square roots to several decimal places, calendar arithmetic held entirely in the head.
Doing it repeatedly is rarer still. Scheepers's record, as the championship itself states it, is four consecutive medals by 2023 and a further third place in a higher age band in 2025. That is a career rather than a single viral moment, and it has been built almost entirely off the radar of mainstream news.
| Person | Country | Milestone | Age / Stat |
|---|---|---|---|
| Chirag Rathi | India | A construction labourer's son in Saharanpur, doing eight-figure arithmetic | Age 13 |
| Stiaan Scheepers | South Africa | Junior Mental Calculation World Championship medals | — |
| Mishti Dharmesh Shah | India | Mental Calculation World Cup 2024 | — |
| Hua Wei Chan | Canada | Finishing second at the 2012 Mental Calculation World Cup | — |
| Naofumi Ogasawara | Japan | Winning the 2012 Mental Calculation World Cup | — |
What is documented — and what is not
✓ Documented
- Third place, Junior 2 (Under-15s), JMCWC 2023, 2,336 points
- Described by the organisers as his fourth consecutive JMCWC medal
- Third place, Senior (Under-20s), JMCWC 2025, 2,663 points
- Field sizes: 70 competitors from 13 countries in 2023; around 80 from 15 countries in 2025
? Unverified, disputed or wrong
- Date of birth and age are not stated in any source used
- Home city, school and training method are not documented
- His placing at the 2024 championship is not stated in the material checked here
- No interview with him appears among these sources
Questions people ask about Stiaan Scheepers
How old is Stiaan Scheepers?
No source used here gives his date of birth or age. The only guide is the divisions he entered: Under-15 in 2023 and Under-20 in 2025.
What did Stiaan Scheepers do?
He took third place in the Under-15 division of the Junior Mental Calculation World Championship in 2023 with 2,336 points, which the organisers recorded as his fourth consecutive medal, and third in the Under-20 division in 2025 with 2,663 points.
Has Stiaan Scheepers won a world championship?
Not according to these results. He has finished third in his division in 2023 and 2025, and the organisers credit him with four consecutive medals by 2023, but no source here records an outright title.
What is the Junior Mental Calculation World Championship?
An annual competition held in Bielefeld, Germany, with three age bands: Junior 1 for Under-12s, Junior 2 for Under-15s and Senior for Under-20s. The 2025 edition was organised by Caroline Merkel and drew around 80 competitors from 15 countries.
What kind of problems are set?
The main event is a two-hour paper covering several categories of mental arithmetic, including addition, square roots and calendar calculation, where a competitor names the weekday for a given date.
Is Stiaan Scheepers on Wikipedia?
No Wikipedia article on him was found among the sources used for this page.
Where is Stiaan Scheepers now?
Not documented. The championship results pages give placings and scores only; nothing in them describes where he lives, what he studies or whether he still competes.
Who else competes at this level?
The 2025 field included competitors from Algeria, Bulgaria, the Czech Republic, Egypt, Germany, Hungary, India, Japan, Mexico, Panama, Qatar, Serbia, South Africa, Turkmenistan and the United Arab Emirates.
Quick quiz: how well do you know Stiaan’s story?
In which German city is the Junior Mental Calculation World Championship held?
What was Stiaan Scheepers's score when he finished third in the Under-20s in 2025?
How many consecutive medals had he won by the 2023 championship?
Sources
- Junior Mental Calculation World Championship 2023: Results — World Mental Calculation, 2023-10-05
- Junior Mental Calculation World Championship 2025: Results — World Mental Calculation, 2025-10-15
- Junior Mental Calculation World Championship 2024: Results — World Mental Calculation, 2024-09-29
Checked by the Geniuses.club editorial team. Ages are given as of September 2026.
Discover More Child Prodigies
50+ stories of contemporary young geniuses changing chess, music, science, and art.
Explore All Prodigies →Related Child Prodigy Profiles
Mishti Dharmesh Shah🇮🇳 India — Two second places in Paderborn…
Chirag Rathi🇮🇳 India — A construction labourer's son in Saharanpur…
Hua Wei Chan🇨🇦 Canada — He can multiply two three-digit numbers in his head…
Naofumi Ogasawara🇯🇵 Japan — A Japanese abacus teacher beat 31 rivals in Giessen and…
Tomohiro Iseda🇯🇵 Japan — Eight-digit multiplications and six-digit square roots…
Tetsuya Ono🇯🇵 Japan — Second in Bielefeld by 28 points…