High number three includes calculus, linear algebra, probability theory and mathematical statistics. Senior three is an elective course in high school mathematics, also called advanced mathematics or mathematical analysis. It is the highest level course in high school mathematics curriculum, mainly involving calculus, sequence, series, vector, space geometry and so on. It is one of the basic courses of college mathematics. Calculus is the core content of Mathematics III, including limit, derivative and integral. Sequence and series are another important content in Mathematics III, including geometric series, arithmetic progression, harmonic series and geometric series. Vector and space geometry is another important branch of Mathematics III, including the basic concept of vector, vector operation, plane vector and space vector, equation of straight line and plane, etc. The study of Math III needs a certain mathematical foundation, including the knowledge of Math I and Math II. The study of Mathematics III needs to master the basic concepts and theorems of mathematics, and understand the thinking methods and problem-solving ideas of mathematics. The study of Mathematics III needs to pay attention to the combination of theory and practice, the cultivation of thinking ability and the improvement of practical problem solving ability.