Primary school mathematics classroom teaching activities are faced with different personalities of life, which should be a dynamic generation process. Therefore, it is particularly important to deal with the relationship between pre-class presupposition and classroom generation in daily primary school mathematics classroom teaching. It is not only related to the determination of teachers' mathematical goals, but also related to whether the teaching goals are in line with students' reality. It is also related to improving the effectiveness of classroom teaching and making a class effective.

When answering the question "How to effectively regulate the classroom and handle the relationship between classroom presupposition and classroom generation", Qian Jinduo, a famous special-grade teacher in China, said: "In the process of curriculum implementation, there are often different degrees of deviations between the preset teaching process and the real situation in the classroom. This deviation is the expression of students' personal knowledge, direct experience, life world and other children's cultures, and it is the self-interpretation of the collision between students and teaching materials, which has many valuable elements. In this process, students' wisdom is blooming, their emotions are colliding and their horizons are expanding, which is more valuable than any so-called knowledge goal. "

I think Mr. Qian's words clarify three aspects of dealing with the relationship between pre-class presupposition and classroom generation: first, pre-class presupposition should fully understand students and rationally understand generation; Second, classroom teaching should effectively develop resources and choose and generate resources wisely; Third, teaching evaluation should be timely, accurate and skillfully generated.

Now, I will think, explore and talk about the presupposition and generation in primary school mathematics classroom teaching from these three aspects. First, the pre-class presupposition should fully understand the students and generate rational knowledge.

Before a class, we always carefully design each class, and every design and activity of teaching can't be separated from the preset before class. By default, we should directly face the students' mathematical reality, that is, design teaching from the students' existing knowledge base, life experience, cognitive rules and psychological characteristics, and determine the teaching objectives that meet the students' actual needs, which requires us to conduct pre-class research. What are you investigating? For example, what is the starting point of students' learning? What are the students more interested in during the learning process? What is the distance between old knowledge and new knowledge? Do you need to give some hints to the students? Will these hints reduce students' thinking intensity? What questions might students ask? What are the possible answers to the students' questions? These are the premises that teachers should fully understand. Because only by working hard on presupposition and rationally understanding generation can we better solve the problem of classroom generation.

For example, in the application problem teaching of fractional (percentage) division, students show such a set of comparative exercises after experiencing the example teaching. (1) The learning ability of the brain is the most vigorous in childhood and adolescence. When people reach the age of 65, brain cells lose about 3/ 10 of the total number of cells, about 300 billion. Please calculate, what is the total number of brain cells? (2) Children and adolescents have about1000 billion brain cells. By the age of 70, brain cells will lose about 60% of the total number of cells. Please calculate how many billions of brain cells will be lost after 70? After the students finish the calculation, inspire them to associate. The students exchanged ideas with each other, and some said, "There were so many brain cells in adolescence. Are brain cells being used more and more? " Some said, "I don't think the more you use, the smarter you are." Because my father once said that the more you use your brain, the smarter you are. Some said, "I think we should seize the present study time, study hard and seize today." "Otherwise, if the young don't work hard, the old will be sad." Someone said, "Teacher, when people get old, the total number of brain cells will be lost by about 3/ 10. Isn't it pitiful that the brain cells of the elderly have decreased so much? " Some said, "I think we should respect the old people around us." Some said: "I think we should study hard when we are young, become scientists when we grow up, and try to prevent brain cells from losing and prevent the brain function of the elderly from deteriorating."

It can be seen that in the implementation of the course, students learn from the acquisition of mathematical knowledge to the understanding of cherishing the meaning of time, and then how to care for the elderly, so that students can experience the importance of time and life and feel the necessity of caring for the elderly, which embodies that "teaching is always education"; However, we also see that the careful presupposition before class makes the teaching activities generated in the classroom become a process for students to experience noble moral life and rich life, and to increase their mathematical knowledge and improve their personality. As Mr. Qian said, in this process, students' wisdom is blooming, their emotions are colliding and their horizons are expanding, which is more valuable than any so-called knowledge goal.

Second, classroom teaching should effectively develop resources and choose and generate resources wisely.

The Mathematics Curriculum Standard points out that the "realistic" mathematics learning content can be what students see, hear and feel in their lives, or the "reality" that students can think or operate in the process of mathematics learning. This requires us not only to respect students' life experience and learning reality, but also to apply mathematics in the actual background, actively use mathematical thinking methods to solve problems, and attach importance to the process of exploration and application. This means that teaching resources sometimes have to go from "students" to "students". Therefore, we should be good at using the "realistic" learning psychology of primary school students to organize classroom teaching, effectively develop resources, and wisely screen and generate them.

For example, after teaching the "Preliminary Understanding of Fractions", I showed a judgment question: "Divide a circle into two parts, and each part must be half of the circle. Right? " The class is divided into two camps, some are right and some are wrong. Faced with students' different answers, I didn't make a decision immediately, but asked the two sides with different opinions to recommend two representatives and classmates to discuss before expressing their opinions. The little debate began. Representatives of both sides each hold a round piece of paper, and both are determined to convince each other. The representative of the square divided the circle in his hand into two parts and asked, "Did I divide this circle into two parts?" The other representative nodded and replied, "Yes, yes." Zheng Fang held up half a circle and asked, "Is this half of the circle?" The other party: "Yes, yes." The positive side pursued the victory: "Since it is half,

Why not agree with this statement? "At this point, I saw the other representative conveniently tear off a piece of paper from a round piece of paper, held up two parts and asked loudly," Are these two copies? Zheng Fang quickly replied, "Yes." "The other party then held the smaller one in front of him and asked in a challenging tone," Is this half of a circle? " Fang Tuo's confidence is not very good. He whispered, "No". The opponent is aggressive: "Since it is not half, why do you agree with this statement?" Zheng Fang nodded convincingly and stood embarrassedly in the opposing team.

It can be seen that when students have conflicting views, teachers do not simply make a "ruling", but skillfully use students' aggressive psychology, consciously introduce the pros and cons into the debate situation, effectively develop new generating resources, make the individual attention of both sides of the debate effectively focus on the "focus" of the debate, and the effective value of thinking orientation can be more inclined to the internal construction of knowledge, and students' construction of knowledge is more solid.

Third, teaching evaluation should be timely and accurate, and generated skillfully.

"Mathematics Curriculum Standard" clearly points out that students should initially form the consciousness of evaluation and reflection. Therefore, it is necessary to break the traditional evaluation system, return the power of evaluation to students, and let evaluation become learning.

Satisfied, please adopt.