“问题情境”是教师在课堂教学中,依据教材特点,有目的、有计划地设置适宜障碍,这些障碍或是实际问题或是纯数学问题,去引起学生的求索,对疑难问题积极思考,激起学生的求知欲,使学生进入:“心求通而未通,口欲言而未能”的境界.“数学模型”是根据某一事物系统特有的内在规律,采用形式化的数学语言或符号,概括地或近似地表达系统规律的数学结构.简单地说数学模型就是对实际问题的一种数学表述.“建立模型”包括对实际问 “Problem situation ” is the teacher in the classroom teaching, according to the characteristics of teaching materials, purposeful and planned to set appropriate obstacles, these obstacles or practical problems or purely mathematical problems, to arouse the students’ search, positive thinking on difficult problems , Arouse the student’s curiosity, make the student enter: “Mathematical model ” is based on the intrinsic law of a particular system of things, using Formal mathematical language or symbol, general or approximate expression of the mathematical structure of the system rules .Mathematical model is simply a mathematical representation of the actual problem. “Build model ” includes the actual question