Six free world banks of olympiad problems for STEM teachers
[[{“value”:”
CC-BY, provided by the author
Picture 1. The Pythagoras grid: countries against years.
It all started in 2004, when my son Nikolaos began taking part in mathematics competitions in Greece, and I had to find problems for him. I teach mathematics, so I thought this would be easy. It was not. The papers of the Greek competitions were scattered, some only in print. When he started preparing for the International Mathematical Olympiad, things became harder still: every country publishes its olympiads on its own website, in its own language and format, and many older papers survive only as scanned pages.
So I began collecting. First for him, then for anyone who might be looking for the same thing. In 2007, in Vietnam, Nikolaos won a silver medal at the IMO. Little by little, the collection grew into eisatopon.gr, a Greek website I started in 2011, with recreational mathematics, competition problems and notes on the history of mathematics. And the collecting did not stop.
More than twenty years after that first search, I have been able to bring the material together in one place, free for everyone. What began with mathematics now covers six sciences.
Six banks
These are the numbers on 3 November 2026. They grow continuously, as new competitions and years are added.
| Bank | Science | Problems |
| Pythagoras | Mathematics | 68,613 |
| Archimedes | Physics | 3,741 |
| Democritus | Chemistry | 3,326 |
| Antikythera | Informatics | 3,906 |
| Aristotle | Biology | 6,373 |
| Hipparchus | Astronomy and astrophysics | 2,084 |
| Total | 88,043 |
Pythagoras is the largest. It covers 81 countries, from 1894 to today: national olympiads and team selection tests, regional olympiads, every IMO since the first one in 1959, the Kangaroo and university contests. Archimedes starts with the first International Physics Olympiad in 1967 and adds national and regional competitions. In Antikythera, the informatics tasks keep what a programmer needs: input and output formats, constraints, subtasks and sample tests. Democritus, Aristotle and Hipparchus do the same for chemistry, biology and astronomy.
All six work the same way, so a teacher who knows one knows them all. A grid shows countries or competitions against years, and one click opens a paper. You can also search for a word, such as “triangle”, “pendulum” or “photosynthesis”, or browse by topic. Every problem is in English, with careful mathematical and scientific notation, figures and tables, and every paper names its organiser.
There is no registration and no advertising. A “My problem set” panel lets a teacher collect problems from different competitions, give the set a title and print it, with the source of each problem. A “Share” button sends a single problem to a classmate or a colleague, as a link or a picture, and one link can share a whole paper or a whole competition. A whole competition can also be downloaded as a LaTeX file.
Statements, not solutions
The banks hold problem statements only and this is deliberate because the most valuable part of a hard problem is usually the thinking that happens before the solution.
Students are not left alone, though; next to every problem there is an optional “Ask AI” button. It opens the student’s own assistant (ChatGPT, Claude, or Gemini) with the problem already written in, and the student chooses: one hint only, a full solution, or a check of his or her own solution, step by step. The banks keep no AI answer keys of their own, and the page reminds students that AI answers can be wrong and that every step must be checked. AI can help, but it should not replace the student’s own reasoning or the teacher’s judgement.
What classrooms taught me
In my years in Greek secondary schools, olympiad problems were never popular with most students. They were preparing for the national university entrance exams and saw little point in spending an hour on a problem that would never appear in a test. I suspect many colleagues know this.
But in almost every class there are one or two students who are different. They finish the exercise and look up, waiting. They are not always the ones with the best grades. For them, a good problem is not another assignment; it is an invitation. And often the person looking for that problem is not a teacher at all, but a parent who wants to encourage a child’s curiosity.
These banks are for them: the curious students, the teachers who want to offer something beyond the textbook, and the parents who would like to help but do not know where to start.
Some ideas for teachers
A worksheet in a few minutes. Search for a topic, pick the problems that suit your class and print them as a set. A mathematics teacher might choose problems on divisibility, a physics teacher on electric circuits, a biology teacher on inheritance.
Start from your own country. Students are often surprised that their country has olympiads with decades of history. Open its row, choose a year, and compare it with a paper from another continent. The problems differ, but they often call for related ways of thinking. On a phone, the grid becomes a simple list of countries, so students can do this on their own phones.
CC-BY, provided by the author
Picture 2. Pythagoras on a phone: the home screen and the country list, with Greece opened.
One hard problem a week. A single problem on the classroom wall, with no grade and no deadline, can start more discussion than a long list of exercises.
Connecting subjects. Many physics olympiad problems are, at heart, good mathematics, and informatics tasks often hide combinatorics or graph theory. A mathematics teacher and a physics teacher could take a pendulum problem together: first the physical assumptions, then the mathematical model.
CC-BY, provided by the author
Picture 3. Archimedes, the physics bank, with its topic filters and printable problem set.
A bank that keeps growing
Building the banks has meant much more than collecting PDF files. Papers come in many languages and formats; many need retyping, translation, or redrawing of figures and tables. New papers are added, old ones are checked, and mistakes are corrected when they are found.
The problems remain the work of their authors and of the organisations that set them. The banks are independent educational projects; they are not official archives and have no organisational link with the bodies that run the competitions. Every problem names its source, and any organiser can ask for a correction or for removal.
Why a hard problem matters
People sometimes ask me what a student gains from a problem he or she cannot solve. For me, it is a journey. You read the problem, you try an idea, it fails, you try another. Perhaps you leave it and come back the next day, or talk about it with a friend. And sometimes the idea comes, and with it a joy that no grade can give. Even when it does not come, the hour was not wasted: the student has been thinking freely, something a crowded school timetable often leaves little time for.
Not every olympiad problem suits every student, and choosing well is the teacher’s art. But every curious student deserves to meet a problem that truly makes them think. I hope these banks make that meeting a little easier, in any country, and I would be glad to hear from Scientix colleagues who try them.
Links:
- Pythagoras: Mathematics
- Archimedes: Physics
- Democritus: Chemistry
- Antikythera: Informatics
- Aristotle: Biology
- Hipparchus: Astronomy and Astrophysics
About the author
Sokratis Romanidis is a mathematics teacher, an author, and the creator of eisatopon.gr, an educational website he started in 2011. He has written Algebra in Mathematical Olympiads (Kedros, 2006, in Greek), two books of mathematics competition problems for the fifth and sixth grades of primary school and, together with Efi Gyrichidou, two mathematics study guides for the second year of lower secondary school.
Pictures: screenshots by Sokratis Romanidis, CC BY 4.0. The licence covers the author’s own screenshots and does not change the rights attached to third-party competition material shown in them.
The post Six free world banks of olympiad problems for STEM teachers appeared first on Scientix blog.
“}]]