《算术平方根》一节的教学重点是理解算术平方根的意义,难点是它的求法及符号的表示,关键是算术平方根“a~(1/2)(a≥0)”的引入.现行教材对算术平方根“a~(1/2)”的引入设置欠佳,为什么要引入符号“~(1/2)”的说理太形式化,与之相关的预备知识铺垫太少,文中给出了处理这个问题的教学建议. The key point in the section of “Arithmetic square root” is to understand the meaning of the square root of arithmetic, the crux of which is to find its solution and sign, the key point is the introduction of arithmetic square root “a ~ (1/2) (a≥0) Teaching materials for arithmetic square root ”a ~ (1/2) “ introduction of poorly set, why the introduction of the symbol ”~ (1/2) " argument is too formal, too little preparatory knowledge associated with it , The paper gives the teaching suggestions to deal with this problem.