As a people's teacher, one of our tasks is classroom teaching. Teaching experience can be summarized in teaching reflection, so how to write teaching reflection is appropriate? The following is my reflection on the classification teaching of mathematical triangles in primary schools, hoping to help everyone.

Reflections on the classification teaching of mathematical triangles in primary schools 1 The classification of triangles is a teaching activity carried out by fourth-grade primary school students after they have a preliminary understanding of triangles. I think classification is a mathematical idea, and it is a process of orderly dividing and combining things according to certain standards. The classification of triangles lies in giving students a mathematical model, which lays a knowledge foundation for students to better apply triangles in the future and further understand and study triangles. In order to effectively integrate and implement the three-dimensional goals in the classroom, I designed it like this:

(A), create a situation to stimulate interest in the introduction

At the beginning of the class, I first created a mathematical situation for students to classify the students in the class according to certain standards, such as: classifying boys and girls according to gender; According to the group ... according to age ... the purpose is to make students pave the way for triangle classification from multiple angles, create a happy emotional state for students, and make students naturally enter the best learning state.

(B), to explore cooperation and exchanges

The teaching of a class focuses on guiding students to operate, classifying triangles cut by students themselves and exploring classification methods. In the process of exploring triangle classification, I first change the way of presenting knowledge, so that students can operate, observe, reason, verify and summarize with questions. Guide students to explore independently, cooperate and communicate, and find problems in communication. Students begin to operate and divide the triangle into angles: three angles are acute angles, one angle is right angle and the other angle is obtuse angle, and then guide the students to name them respectively. Let me summarize it in the form of a collection. Then ask the question: how to divide it? The students proposed dividing by edges. By measuring the side length, students divide triangles into three categories: isosceles triangles, equilateral triangles and equilateral triangles. Teachers and students know isosceles triangle and equilateral triangle together. After teaching, some conceptual problems have been completed, which makes students have a further understanding of concepts. In the process of consolidating the knowledge learned, students not only cultivate their practical ability, but also pay attention to the cultivation of their thinking ability, so that students can comprehensively use the knowledge and skills they have learned to solve problems and cultivate their application consciousness, practical ability and innovative spirit. The classification of triangles is a process that allows students to create and experience the fun of learning mathematics with their heart, and allows students to operate, think positively, communicate with classmates and show themselves under the guidance of teachers.

(3) Consolidate knowledge and improve ability

I designed a step-by-step consolidation review question, so that students can always consolidate their knowledge and expand their thinking in a pleasant learning atmosphere, so that the three-dimensional goals of knowledge and skills, processes and methods, emotional attitudes and values complement each other and blend into one, thus achieving the integration of the three-dimensional goals.

Reflections on triangle classification teaching in primary school mathematics II. The classification of triangles is a teaching activity carried out by fourth-grade primary school students after they have a preliminary understanding of triangles. Classification is a mathematical idea, and it is a process of orderly dividing and combining things according to certain standards. The classification of triangles lies in giving students a mathematical model, which lays a knowledge foundation for students to better apply triangles in the future and further understand and study triangles.

At the beginning of the class, I seized the valuable activity of classifying triangles, guided students to classify ships made of triangles, and let students operate and explore the classification methods. In teaching, how to prevent students from classifying triangles according to different standards and introduce students into the level of classifying triangles according to edges? I changed the presentation of knowledge to conform to students' cognitive rules, and classified the triangles under the two standards together, focusing on the division of angles, so that students could find the characteristics of acute triangle, right triangle and obtuse triangle, and divide the triangles into these three categories according to the angle standard. Then let the students have a look at what new discoveries they have made with the tools in their hands, and let them find isosceles triangles and equilateral triangles. Then let the students feel that they can be divided into isosceles triangles, equilateral triangles and equilateral triangles according to the characteristics of the sides of triangles, so as to further understand the inclusion relationship between them. It highlights the students' dominant position, and students have experienced the process of independent inquiry, thus gaining a successful experience.

However, there are also some problems in teaching, such as insufficient communication time, ignoring unsuccessful students and vulnerable students, and less communication time, especially why equilateral triangle is a special isosceles triangle, which fails to make students fully understand. From the teaching of this section, I think teachers should fully consider the different levels of students, which should be paid attention to in future teaching.

Reflections on the teaching of "triangle classification" in primary school mathematics III. This course first guides students to classify triangles according to the types of angles, and then designs a series of learning activities around the classification of triangles: drawing a picture, connecting them, folding them, dividing them, spelling them, guessing them and so on. The purpose is to let students deeply understand the characteristics of various triangles in the operation process. It should be said that the preparation is sufficient and the students' interest in learning is also high. But there are also many areas that need to be improved. Let's reflect after class:

Teaching reflection fragment 1:

What is really overlooked in the process of preparing lessons is that students seem to be confused about the concepts of diagonal and triangle. For example, there is such a problem in after-class exercises:

Observe the figure and say that this figure has () right triangles; There are () acute triangle; There are () obtuse triangles. In my homework, I found that many students wrote 10 acute triangle.

I interviewed several students and found that when they count acute triangles, they will count how many acute angles this figure has. It seems that the students have confused the concepts of acute angle and acute triangle.

Looking back on classroom teaching, a detail caught my attention: after understanding the classification of triangles, please draw an acute triangle, a right triangle and an obtuse triangle in your notebook. When traveling, I found that several students drew acute angles, right angles and obtuse angles. But when dealing with this problem, they just reminded some of their students that they were drawing triangles, and they changed.

I think the reason for the failure of this teaching is that I didn't grasp the teaching resources generated in the teaching, but blindly aimed at completing my own teaching tasks.

If this happens, students' mistakes should be used as teaching resources to guide them to distinguish, and then the last topic should be put forward so that students can find right triangle, acute triangle and obtuse triangle in this figure, which should play a better teaching effect.

Teaching reflection fragment 2:

In the teaching of "guessing", this lesson makes full use of the characteristics of good performance of audio-visual media, and the effect is good When students guess the third figure, at first 100% students think that this triangle must be an acute triangle. After many questions, two or three students raised their hands to show that they still have different views. After asking them to answer, most students still looked at the teacher with doubts. At this point, after demonstrating three possible situations with courseware, the students suddenly realized that it was possible. I believe this lecture will leave a deep impression on the students.

Reflections on the teaching of "triangle classification" in primary school mathematics 4. "The Classification of Triangle" is the content of page 83-84 of Unit 5 in the second volume of Grade Four in primary school, and it is a teaching activity after students have a preliminary understanding of triangle.

It is not too difficult for students to learn such knowledge, but if students do not have a deeper understanding of learning, they will often make mistakes in the later comprehensive exercises. Personally, I think students should understand three different triangles classified by angle from several different aspects:

1, understand the characteristics of each corner of a triangle. Through the analysis of diagonal characteristics, we know that each triangle has two acute angles, so we should determine what a triangle is according to what the third angle is. Students can generally master this knowledge well.

2. Obviously, the triangle can also be determined according to the maximum angle. If the largest angle is acute, it is an acute triangle, a right triangle and an obtuse triangle.

3. After learning isosceles triangle, students should have a clear understanding of its characteristics, and at the same time, they should be associated with acute triangle, right triangle and obtuse triangle, and understand that isosceles triangle is defined according to the characteristics of sides, while acute triangle, right triangle and obtuse triangle are classified according to the characteristics of angles. They are not contradictory and can coexist.

4. When learning the classification of triangles, in order to let students better grasp the relationship between them, I repeatedly ask students to choose which graph can be used to express the relationship between them.

5. After learning the knowledge of the sum of the angles in a triangle, in order to deepen students' understanding of the knowledge and enable them to use it skillfully, we can show some comprehensive exercises, such as: "The largest angle of a triangle is 60 degrees, what triangle is this, and the sum of the two acute angles in an obtuse triangle is () 90 degrees, and so on.

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