1, the elementary arithmetic order of integer, decimal and fraction (including checking calculation). 2. Formulas for calculating the perimeter and area of various plane figures. 3. Formulas for calculating the surface area and volume of various three-dimensional graphics. 4. Constant quotient law. 5, product change law. 6, the length of the unit, unit area, unit volume difference and progress between units. 7. The essence of decimals. 8, the ratio between quality units. 9. Conversion between singular and complex numbers. 10, rewriting times (rewriting is in thousands or billions. ) 1 1, and find the approximate number. 12, reciprocity of fractions and percentages. 13, multiple, common multiple, least common multiple. 14, divisor, common divisor, greatest common divisor. 15, factor, factorization prime factor 16, general score and approximate score. 17, find the unknown (solve the equation). 18, ratio and ratio, solution ratio. 19, solving problems (addition, subtraction, multiplication and division, addition, subtraction, multiplication and division, normalization, etc. ).