学具操作是一种定向的心智活动,其方向决定于教学目标,其过程和结果要有利于揭示概念的本质特征和知识间的内在联系。所以,在学生动手操作前安排一个定向指导环节,一般来说是必不可少的。 The operation of learning tools is a kind of directed mental activity whose orientation is determined by the teaching goal. Its process and result should be helpful for revealing the intrinsic characteristics of concepts and the internal relations between them. Therefore, it is generally essential to arrange a targeted instruction before the student hands-on operation.