Three world titles
The Junior Mental Calculation World Championship is the age-group event of competitive mental arithmetic, a discipline with formal rules, timed papers and published results. Živanović won its under-12 division in 2023, when he was 11. He then moved up an age group and won the under-15 division in 2025 and again in 2026.
World Mental Calculation, which organises and publishes the results, carries his placings across the 2023, 2024, 2025 and 2026 championships. A report from the Mind Sports Olympiad's mental calculations championship in April 2024 recorded his age as 12, which fixes his birth year independently of any profile.
What the competition involves
Competitive mental calculation is not a single test. The championships are decided across disciplines of the same general family: adding long columns of multi-digit numbers, multiplying large numbers together, extracting roots, and calendar calculation, in which a competitor is given a date and must name the day of the week. Every event is timed, and accuracy and speed are scored together.
This is a narrow skill, rigorously measured. There is no interpretation in the marking and no judge to persuade. A competitor's score is the number of correct answers produced inside the limit, which makes the discipline unusually clean as evidence of a specific cognitive ability.
Moving up an age group
The step from under-12 to under-15 is the one that tests whether a young calculator is precocious or simply good. In age-group competition, the child who wins early is often beaten within two years by children who have caught up physically in working memory and practice hours.
Živanović won at the top of one age band and then won twice at the top of the next. That pattern, a title in 2023 followed by titles in 2025 and 2026, is what distinguishes a sustained record from a single good day.
What is documented, and what is not
Everything on this page comes from published championship results. No profile interview, school detail, family information or training account appears in the sources used here, and none is invented. His town, his school and his coaching, if any, are unrecorded.
That is unusual for a record of this kind and, in its way, useful. The evidence is entirely in the standings: a name, an age group, a year and a placing, published by the body that ran the event.
Why mental calculation still has champions
A machine has been able to out-calculate any human being for eighty years, which makes competitive mental arithmetic look, at first glance, like a discipline in search of a purpose. Its practitioners answer that the events measure something calculators cannot: how much a person can hold in working memory, manipulate and retrieve under time pressure, without writing anything down.
That is why the world championships have continued to attract competitors, and why the junior events are watched closely. The children who win them are demonstrating a specific and measurable capacity at an age when it can still be developed. A competitor who takes the under-12 title and then the under-15 title twice, as Živanović has, is not repeating a trick. He is improving inside a discipline whose scoring leaves no room to disguise whether he has.
| Person | Country | Milestone | Age / Stat |
|---|---|---|---|
| Wenzel Grüß | Germany | Most Versatile Calculator, 2018 Mental Calculation World Cup | Age 9 |
| Andrej Živanović | Serbia | Junior Mental Calculation World Championship titles | Age 11 |
| Marc Jornet Sanz | Spain | Second place at the 2010 and 2014 Mental Calculation World Cups | Age 16 |
| Willem Bouman | Netherlands | Seven decades of mental calculation; eldest competitor at the 2024 World… | Age 20 |
| Freddis Reyes Hernández | Cuba | Winning multiplication and the Memoriad Trophy at the 2012 Mental… | Age 27 |
What is documented — and what is not
✓ Documented
- Won the Junior Mental Calculation World Championship under-12 title in 2023
- Won the under-15 title in 2025 and again in 2026
- Recorded aged 12 in an April 2024 Mind Sports Olympiad report
? Unverified, disputed or wrong
- No profile, interview or biographical detail exists in these sources
- No town, school or coaching information is published
- No IQ figure or other test score is on record
Questions people ask about Andrej Živanović
How old is Andrej Živanović?
He was born in 2012. A Mind Sports Olympiad report in April 2024 gave his age as 12, which is consistent with that.
What has Andrej Živanović won?
The Junior Mental Calculation World Championship under-12 title in 2023, and the under-15 title in 2025 and 2026.
What is mental calculation competition?
A timed sport of arithmetic performed without aids, decided across disciplines including multi-digit addition and multiplication, root extraction and calendar calculation.
Where is Andrej Živanović from?
Serbia. No town, school or family detail appears in the sources used here, which are championship results rather than profiles.
Is Andrej Živanović on Wikipedia?
No Wikipedia article on him was found. His record is documented by World Mental Calculation's published results.
What is his IQ?
No IQ figure for him appears in any source used here. His documented ability is measured in championship scores, not test numbers.
Who are his parents?
No source used here names his parents or gives any family detail.
Does he still compete?
His most recent documented result is the 2026 under-15 title. Nothing later appears in the sources used here.
Quick quiz: how well do you know Andrej’s story?
Which title did Andrej Živanović win in 2023?
In which years did he win the under-15 title?
Which of these is a mental calculation discipline?
Sources
- Junior Mental Calculation World Championship 2023: Results — World Mental Calculation, 2023-10-05
- Junior Mental Calculation World Championship 2024: Results — World Mental Calculation, 2024-09-29
- Junior Mental Calculation World Championship 2025: Results — World Mental Calculation, 2025-10-15
- Junior Mental Calculation World Championship 2026: Results — World Mental Calculation, 2026-09-15
- MSO Mental Calculations World Championship 2024: Results — World Mental Calculation, 2024-04-15
Checked by the Geniuses.club editorial team. Ages are given as of September 2026.
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