Effective mathematics learning is based on students' objectivity.
Based on reality. Sophomore students often see the phenomenon of "a few less" in their daily life experiences, but they rarely use "a few less" to describe it. In the previous research on addition, although the addition of the same number has been calculated, it is not required to say what it is.
In the teaching process of this class, I think there are four points as follows.
The income is:
(1) Understand "several" in specific situations. First, make up the students to count the number of chickens and rabbits according to the group number, list the formulas, and have a preliminary perceptual understanding of several identical numbers; Then let the students operate the disc by hand, process the newly formed perceptual knowledge into representations, and experience a few things in their own hands; Then guide the students to observe the flowers from different angles, calculate the number respectively, and further understand the practical significance of the flowers in the comparison. In teaching, students experience comparative perception by looking at pictures and counting, and initially establish the representation of "Ji" in vivid and concrete situations.