The International Mathematical Olympiad (IMO) is an annual six-problem, 42-point mathematical olympiad for pre-collegiate students and is the oldest of the International Science Olympiads.

[1] The first IMO was held in Romania in 1959. About 100 countries send teams of up to six students,

[2] plus one team leader, one deputy leader, and observers.

[3] Ever since its inception in 1959, the olympiad has developed a rich legacy and has established itself as the pinnacle of mathematical competition among high school students.

The paper consists of six problems, with each problem being worth seven points, the total score thus being 42 points. No calculators are allowed. The examination is held over two consecutive days; the contestants have four-and-a-half hours to solve three problems per day. The problems chosen are from various areas of secondary school mathematics, broadly classifiable as geometry, number theory, algebra, and combinatorics.

Usually, 2nd week of December every year.

The participants are ranked based on their individual scores. Medals are awarded to the highest ranked participants, such that slightly less than half of them receive a medal. Subsequently the cutoffs (minimum scores required to receive a gold, silver or bronze medal respectively) are chosen such that the ratio of gold to silver to bronze medals awarded approximates 1:2:3. Participants who do not win a medal but who score seven points on at least one problem receive an honorable mention.