The Olympiad mainly includes four plates: one is the calculation plate, which contains various calculation skills; Second, the counting part, including permutation and combination, classification and enumeration; Third, the theoretical part, including odd and even numbers, and the composite number of prime numbers; And fourth, the part of decimal problem solving, including chickens and rabbits in the same cage, cows eating grass, sum and difference, average, profit and loss, page number and so on. It has problem-solving skills or formulas.