The International Mathematical Olympiad (IMO) is the World Championship Mathematics Competition for High School students. The first IMO was held in 1959, hosted by Romania, with seven countries participating: Hungary, Bulgaria, Poland, Czechoslovakia, East Germany and USSR. Since then, the participating countries have taken turns in hosting it.The number of participating countries increased to 97 countries from all continents in the 49th IMO. When the IMO first began, each country was allowed up to eight participants. In 1982, this was scaled back to four members, but in 1983 the number was increased to six, which is where it still stands. The contestants must be no more than 20 years old and must not have any post secondary-school education. There is no limit to how many times a person may participate in the IMO, provided the individual meets the age and schooling requirements. The usual size of an official delegation to an IMO is (a maximum of) six students, along with the Leader and Deputy Leader. The student competitor writes two contest papers on consecutive days, with three problems on each day. Each question is worth seven marks. Only a whole number of marks are given. Each invited country can send in up to six problems for consideration for the final competition papers. These submissions are reviewed by the host country’s problem selection committee, and a short list of about thirty questions is made. The choice of the questions on the actual competition papers is made by the International Jury. The International Jury consists of the Chief Delegate (Leader) from each participating country, together with the Chairman named by the host country. Decisions are made by a simple majority vote. The official languages of the IMO are English, French, German and Russian. Since Spanish is spoken in a large number of participating countries, it has become an unofficial “official” language. In recent years, English has been the working language of the International Jury, with the other official languages available whenever required. The International Jury members receive the short list of questions on arrival at the sequestered site. They review these problems and then meet to discuss which problems will be included. An honour system requires delegates to identify any suggested problems that are well known, in text books, or have been used in training programs. Some problems are eliminated as too easy or too hard. After thorough debate, the six problems are chosen, and their wording in all the official languages is agreed. The team leaders translate the problems into all further languages required by their contestants. After that all papers, in all languages, are inspected by all members of the International Jury, to ensure that all translations are appropriate. Meanwhile, the Deputy Leaders and Contestants have arrived at the venue. The Opening Ceremony is held, and the Contest takes place the following two days. Each Contestant has to solve 3 problems within 4½ hours in each of the two days in his/her own language. After the Contest, the Leaders and Deputy Leaders evaluate the solutions of their contestants and hold coordination sessions in order to ensure that the marking has been done correctly and consistently. During these days, the participants enjoy a varied enternainment programme including excursions and games.
The last day is for the Closing Ceremony, and the Gold, Silver, and Bronze medals will be awarded for excellent performances. The International Mathematical Olympiad is an individual competition. Medals are awarded to at most half of the participating students. Gold, Silver and Bronze medals are awarded in the ratio of 1:2:3, so that about 1/12 of the students obtain a Gold Medal, about 1/6 of the students obtain a Silver Medal and about 1/4 of the students obtain a Bronze medal. In order to encourage more students, and to encourage students to solve complete problems, recent practice has awarded a Certificate of Honourable Mention to any student (not receiving a medal) who obtained full marks for at least one problem.