Reflections on quadrilateral teaching 1

This lesson is based on the fact that students have learned triangles and known squares and rectangles. The main purpose is to let students feel the quadrangles with different shapes and master their characteristics. In order to make students learn and master the knowledge of this lesson easily and happily, I mainly consider and design it from the following aspects:

First, proceed from the existing experience, introduce directly and try to judge.

At the beginning of the class, I asked the students to look at the topics in the courseware, and let them talk about their understanding of quadrangles and understand their existing understanding of quadrangles in their minds. Then show the quadrilateral figure of p35 in the book, let each student judge one by one, and tell why it is not a quadrilateral figure, so that students can sum up the characteristics of quadrilateral with their own experience and further improve their understanding of quadrilateral. Here, we pay attention to the application and promotion of students' existing experience, start with the students' foundation, carry out learning on this basis, and gradually improve.

Second, analyze and analyze in many activities, actively participate in it, and gain a deeper understanding.

Pupils are curious and active, and mathematics knowledge itself is boring and abstract. Mastering mathematics knowledge must conform to children's own characteristics. In this class, I let students acquire new knowledge through various activities such as watching, speaking, dividing points, drawing pictures, etc., so that students are in a proactive state in the whole class, which not only cultivates students' hands-on ability and observation ability, but also makes students develop a good habit of being good at thinking and willing to use their brains. Through the judgment and classification activities of quadrangles, students further felt the subtle differences of quadrangles. Some students divide quadrangles according to the learned standards, some students divide them according to whether they are right angles, some students divide them according to how many points they are right angles, some students divide them according to whether the opposite sides are equal, some students divide them according to how many points they are equal, and so on. And they have a deep understanding of quadrangles in the process of actively participating in the discussion and study. Of course, activities need good discipline. In class, I emphasized the methods of group cooperative learning, and each student was divided into four groups. Those responsible for discipline, reporting and recording have their own duties and are in an orderly manner. Let group cooperative learning be more effective and solid.

Third, improve and consolidate what you have learned and broaden your thinking in open questions.

It is one of the teaching objectives of this course to develop students' imagination and cultivate their innovative consciousness and practical ability in open activities. Consolidate two exercises that I designed in the practice stage:

1. There are two long sticks and two short sticks in the schoolbag. Take out two long sticks and a short stick. Three questions were raised:

(1), how to spell a rectangle? What kind of two sticks do you need?

(2) What quadrilateral can you spell? What kind of stick do you need?

(3) What quadrilateral must not be spelled? Why? Through three questions, let students clearly understand the characteristics of quadrangles in an open thinking space and have a deeper understanding of the differences between them, especially the understanding of rectangular squares.

2. Fill in two figures and turn them into two quadrangles, which is of great help and promotion to students' spatial thinking ability and mathematical imagination ability. Pay attention to cultivating students' mathematical literacy.

Of course, I think so, the design is so designed, reflecting on the teaching of the whole class, there are many shortcomings, mainly three:

First of all, the learning tools are not detailed enough. Because they are tailor-made, some learning tools are not fine enough or even rough enough, which will hinder students' learning and classification, as well as the formation and construction of knowledge, and should be paid attention to. At the same time, the case of special quadrangles, such as the special case of concave quadrangles, is not considered. It does not give students a more comprehensive understanding of quadrangles.

Secondly, the summary process after quadrilateral classification is not handled properly, and students' understanding of rectangular squares is not deep enough, which leads to the fact that two sticks in the exercise are not as bright as they should be and need to be reflected.

Thirdly, students' responsibility in group cooperative learning needs to be greatly improved, and more exercises and training should be done in future teaching to make group cooperative learning more effective and efficient.

I have always thought that classroom is an art with regrets. No matter how plump the design is in my imagination and how passionate my teaching is, there will always be problems in my life. Children are smart, so the classroom is more mobile. You can make progress if you don't know enough.

Reflection on Quadrilateral Division Teaching (Ⅱ)

? Quadrilateral is the first lesson of Unit 7 in the first volume of the third grade of People's Education Press. It is not only a course about space and graphics knowledge, but also a highly operational course. Students constantly understand, consolidate and apply new concepts through operation, thus developing their hands-on ability and inquiry ability.

1. I arranged for students to preview before class, giving them enough time to study and think, paving the way for participating in classroom learning, and making learning more purposeful and targeted.

In this class, I introduce a new lesson by checking students' preview, so that we can check the completion of students' preview homework and understand students' perception of quadrilateral, which makes teaching more targeted.

2. In teaching, I attach great importance to students' group cooperative learning and cultivate students' ability to participate in learning in class. The characteristics and properties of graphics in "A Preliminary Understanding of Graphics" are abstract for primary school students. Therefore, when I perceive the characteristics of quadrilateral, rectangle and square, I give students enough time to think and discuss, so that students can abstract the characteristics of quadrilateral, rectangle and square through observation, comparison and thinking. Group cooperative learning can cultivate students' cooperative consciousness, exchange and display the learning achievements of the group, share the experience of others, cultivate students' mathematical thinking and language expression ability, enable students to gain successful experience and enhance their self-confidence in learning mathematics.

3. When I broke through the difficulty of this lesson "the characteristics of rectangles and squares", I chose to let students explore by hands. To this end, I prepared a square and rectangular cardboard for each group in advance, and asked each group to discuss it in groups by measuring, folding and comparing. Then show the results of class discussion and the methods of inquiry. Students have a high interest in participating in the class and cooperate with each other. They measure angles with a triangle ruler, measure sides with a ruler, fold rectangles and squares, and compare the relationship between their sides ... In the activity, students actively participate in classroom learning, and the learning effect is good, which successfully breaks through the teaching difficulties.

This class also has some shortcomings. For the progress of classroom teaching, students only emphasize the use of edges or corners as standards when classifying graphics, which imprisons students' thinking and makes some students' more creative ideas not fully displayed. They should assign homework, let students explore and learn constantly, and extend their enthusiasm for participating in classroom learning to extracurricular activities.

Reflections on Quadrilateral Teaching (3)

? Quadrilateral is not only a course about space and graphics knowledge, but also a highly operational course. Students constantly understand, consolidate and apply new concepts through operation, thus developing their hands-on ability and inquiry ability.

In this lesson, I did better:

1, using a variety of teaching methods to mobilize students' enthusiasm for learning, let students abstract the concept of quadrilateral through observation and comparison in activities, take students' learning as the starting point, guide students to learn the law, and let students learn actively. Teaching AIDS and learning tools also play their due roles. A series of activities, such as finding, circling, speaking, touching and drawing, run through the whole learning process, which greatly mobilizes students' enthusiasm. Students always carry out activities in specific situations created by teachers, study in a relaxed and happy atmosphere, and get to know quadrangle, a new friend, which really makes students actively think and explore, realizes their interest in learning mathematics and cultivates their mathematical ability.

2. Guide students to learn mathematics in life. Pay attention to students' knowledge background and life experience in teaching, fully mobilize students' enthusiasm through activities, and also generate problems through activities. Then through observation, abstract concepts, consolidate concepts, and find quadrangles in life, let students perceive that mathematics comes from life, let students realize that there are quadrangles everywhere in life, stimulate students' interest in learning, and enhance students' consciousness that mathematics comes from life and is used in life. Help students to establish clear concepts.

3. Pay attention to hands-on operation. Quadrilateral is a highly operational course. Students can explore what kind of figure is called quadrilateral through operation, and at the same time they can further understand and consolidate the concept. With the help of activities such as finding, circling, dividing and drawing, students not only consolidate their knowledge, but also cultivate their practical ability, inquiry ability and innovation ability.

Reflections on Quadrilateral Teaching (Ⅳ)

1, verifying mathematical ideas with analogy conjecture.

"Dare to guess and be careful to verify" is a universal law of scientific inquiry and an important way to acquire knowledge. On the basis of students' knowledge that the sum of the interior angles of a triangle is 180, guess the sum of the interior angles of a quadrilateral by analogy. Through measurement, calculation, discussion and communication, it is concluded that the sum of the internal angles of the quadrilateral is 360 degrees. The knowledge gained through personal experience is more firmly grasped. Guide students to learn to explore and summarize the mathematical laws contained in things, and improve their comprehensive ability to use knowledge to solve problems. In the process of inquiry, the mathematical ideas of induction, conjecture and verification are infiltrated, so that students can realize the magic and mystery of mathematics, improve their interest in learning mathematics and enhance their confidence in learning mathematics well.

On this basis, students are guided to divide quadrangles into triangles, which proves that this law is more perfect in theory.

2. Give full play to the main role of students.

The teaching activities in this section give full play to students' main role and create actual situations, thus stimulating students' interest in learning and making the classroom full of vitality. In the teaching of quadrilateral interior angle sum, three steps are designed:

(1) Through hands-on operation, let students discover through experiments that the sum of the internal angles of the quadrilateral is 360 degrees;

(2) Let students find that the sum of the internal angles of the generalized quadrilateral is 360 degrees;

(3) Discuss the application through students.

The whole class is full of the teaching concept of "independence, cooperation, inquiry and communication", which creates a space for galloping thinking and enables students to naturally acquire new knowledge in the process of active thinking and inquiry.

3. Infiltrate mathematical ideas.

In the process of inquiry, the mathematical ideas of induction, conjecture and verification are infiltrated, so that students can realize the magic and mystery of mathematics, improve their interest in learning mathematics and enhance their confidence in learning mathematics well. On this basis, students are guided to divide quadrangles into triangles, which proves that this law is more perfect in theory.

Insufficient:

Students are not allowed to explore and think actively when exploring the internal angles and degrees of quadrilaterals and later exploring the internal angles and degrees of polygons. The teacher's guidance is too much, which limits students' thinking.

In the process of re-teaching, students should be allowed to think, operate and express freely, stimulate their thinking and cultivate their creative ability.

Reflection on quadrilateral teaching (5)

The calculation of parallelogram area is the basis of learning the basic knowledge of plane geometry. Especially, the derivation of parallelogram area formula contains the mathematical idea of transformation. It is of great significance for students to learn and deduce the formulas of triangle and trapezoid area in the future. Summarizing the teaching of this class, I have the following experiences:

First, follow the teaching process of "conjecture-verification-deduction-application"

Before deducing the area formula of parallelogram, I first showed an application problem to calculate the area of parallelogram. Students blurt out and list the formulas. I asked them what this was based on. The student replied, "I guess." Mathematical conclusions must be verified before they can be used and convincing. Then, I asked the students to measure, cut, spell and study it together to find out its universal law. Students first measure the area, then cut the material in their hands along the height of the parallelogram and make it into a rectangle. From this study, it is found that the relationship between rectangle and parallelogram fully embodies the mathematical idea of transformation, and the formula is obtained through induction and verification.

Students participated in the whole process to verify the correctness of the conjecture formula. Make students get an intuitive proof. Further deepen students' understanding of the formula. When students use formulas, they know both why and why, and the application of knowledge reaches the highest level of cognitive process.

Second, pay attention to cooperation and exchange, seeking differences and innovation.

In this kind of class, teachers try their best to create an appropriate atmosphere for students to speak, think and do, and create the necessary situation and space, so that students can learn knowledge, cooperate and communicate, increase their talents and improve their abilities in the process of actively participating in learning activities. In the process of cutting and splicing, some students cut a triangle along the height, and some cut a right-angled trapezoid to make a rectangle. Teachers are surprised at the diversity of methods.

In group discussion, students can express their own "fantastic ideas", which not only broadens their horizons and expands their thinking space, but also reflects their collective wisdom.

Thirdly, in classroom teaching, teachers' adaptability needs to be improved.

In the process of assembling pendulum, although there are various methods, some students are still limited to putting parallelogram in one position. What if they cut and spell from different angles? The teacher's guidance is not in place. Some students rolled the parallelogram into a cylinder, which just overlapped on the two hypotenuses of the parallelogram, and then she folded the triangle in half along the height of the two hypotenuses of the parallelogram, thus dividing the parallelogram into a rectangle and two right-angled triangles, and then put the two rectangles together to find the law.

Because the student's language expression is incomplete, I didn't deeply understand her intention. This shows that teachers' adaptability is poor, and it is necessary to study the teaching materials in depth and have a correct estimate of all kinds of situations that may occur in the classroom.