Arithmetic progression's formula for elementary school olympiad is the nth item = first item+(item number-1)× tolerance, item number = (last item-first item)/tolerance+1, tolerance = (last item-first item) ÷ (item number-/kloc-0.

"Olympic Mathematics" is the abbreviation of Olympic Mathematics Competition, which is an international competition with mathematics as its content and middle school students as its object. It has a history of more than 30 years. As an international competition, the International Mathematical Olympiad was put forward by international mathematical education experts, which exceeded the level of compulsory education in various countries and was much more difficult than the college entrance examination.