Abstract: Because the natural numbers come from the students' operation activities (the operation here includes both the manual operation of the specific object information, and the mental operation of the symbols signifying the specific object information); the addition and subtraction of natural numbers and the four operations that constitute the basis of the natural numbers are derived from the students' operations. Mathematical logical reasoning and its expression form (causal relationship) are also derived from students' operational activities. Mathematics teachers can foster the pioneering spirit of mathematics teaching by learning the psychological knowledge which promotes the generation of students' cognition of mathematics knowledge, and through their own teaching conceptions and experimental tests, etc., to help generate effective activity mathematics teaching for lower grade students.