1.

Counting principle

(about 14 class hours)

(1) classification addition counting principle and step-by-step multiplication counting principle

Summarize the principles of classified addition counting and step-by-step multiplication counting; According to the characteristics of specific problems, we can choose the principle of classified addition counting or step-by-step multiplication counting to solve some simple practical problems.

(2) permutation and combination

Understand the concepts of permutation and combination; The formulas of permutation number and combination number can be derived by using the counting principle, and simple practical problems can be solved.

(3) binomial theorem

Binomial theorem can be proved by counting principle (see example1); Will use binomial theorem to solve simple problems related to binomial expansion.