Knowledge points, lesson plans and teaching reflections on "Quadrilateral" in third grade primary school mathematics

#三级# Introduction A closed plane figure or three-dimensional figure formed by four line segments that are not on the same straight line and connected end to end is called a quadrilateral. It is composed of a convex quadrilateral and a concave quadrilateral. The following is a compilation of knowledge points, lesson plans and teaching reflection related materials for third-grade primary school mathematics "Quadrilateral". I hope it will help you.

Article 1 Knowledge points of "Quadrilateral" in third-grade primary school mathematics Square

Concept: A quadrilateral with four equal sides and four right angles is a square.

Characteristics: There are 4 right angles, and the 4 sides are equal. (A square is both a rectangle and a rhombus)

Perimeter: Perimeter of a square = side length × 4

Rectangle

Concept: One angle is a right angle A parallelogram is called a rectangle.

Characteristics: A rectangle has two lengths, two widths, four right angles, and opposite sides are equal.

Perimeter: Perimeter of a rectangle = (length + width) × 2

Parallelogram

Concept: a quadrilateral with two sets of opposite sides parallel to each other. Opposite sides are parallel and equal, and opposite angles are equal. (Square and rectangular numbers are special parallelograms)

Characteristics: ① Opposite sides are equal and opposite angles are equal. ② Parallelograms are easily deformed.

Perimeter: Perimeter of a parallelogram = the sum of the lengths of the two sides × 2

Trapezoid

Concept: One set of opposite sides is parallel, and the other is parallel. A set of quadrilaterals whose opposite sides are not parallel.

Characteristics: Only one set of opposite sides is parallel.

Perimeter: upper base + lower base + length of both waists

Isosceles trapezoid

Concept: a trapezoid with two equal waists, its two bases The angles are equal and it is an axially symmetrical figure with one axis of symmetry.

Characteristics: One set of opposite sides is parallel and the two waists are equal in length.

Perimeter: upper base + lower base + length of both waists

Rhombus

Concept: A set of parallelograms with equal adjacent sides is a rhombus.

Characteristics: ①All four sides are equal ②Diagonals bisect each other perpendicularly ③A diagonal bisects a set of diagonals respectively

Perimeter: Add the length of two different sides ×2

What are the connections between each quadrilateral?

1. A square is both a rectangle and a rhombus.

2. Square and rectangular numbers are special parallelograms.

3. Is it a square or a special rectangle?

Part 2: Mathematics "Quadrilateral" Lesson Plan for the Third Grade of Primary School 1. Teaching content:

Compulsory Education Curriculum Standard Experimental Textbook (People's Education Press Edition), Volume 1, Page 35 of the third grade.

2. Teaching objectives:

1. Be able to distinguish quadrilaterals from various figures and understand the characteristics of quadrilaterals.

2. By classifying quadrilaterals, you can understand the characteristics of different quadrilaterals, especially the characteristics of rectangles and squares.

3. Cultivate students’ spatial concepts through practical activities.

3. Teaching preparation:

Courseware. Prepare a watercolor pen for each person. Group of Four: Picture of a bag of quadrilaterals.

IV. Teaching process:

(1) Introduction of theme maps.

1. Students, do you like to participate in sports activities? What sports do you like?

2. On the campus of Guangming Primary School, students are also doing various activities. Let’s go and see them together. (The courseware shows the theme picture)

(1) Observe carefully, what graphics did you find on this beautiful campus? (Look for it by yourself first, and then communicate with your deskmates)

(2) Communication and reporting, the graphics students may find are: (answer by name, the courseware flashes alone)

3. Import topics.

There are many shapes on the beautiful campus, such as rectangles, squares, parallelograms, rhombuses, and trapezoids (flash these shapes at the same time). These are all plane shapes, called quadrilaterals. In today's lesson we will study quadrilaterals.

Writing on the blackboard: understanding of quadrilaterals.

4. Initial perception: What kind of shape do you think is a quadrilateral?

(2) Explore communication and summarize characteristics.

1. Hands-on operation.

(1) Paint (let students perceive the surface)

Students, there are many shapes in Chapter 35 of the mathematics book. Can you find the quadrilateral among them? And paint it with your own favorite color. Compete to see who can apply it faster and better.

(2) After finishing painting, communicate with your deskmates and tell them the reasons.

(3) Collective feedback, why are these quadrilaterals and those not?

2. Discuss and summarize the characteristics of the quadrilateral.

(1) Look carefully, what are the characteristics of these quadrilaterals? (Group first, then feedback)

(2) Write on the blackboard based on students’ feedback.

3. Determine the quadrilateral.

Teacher, there are some other shapes here. Can you tell whether they are quadrilaterals? (Use gestures collectively to judge and explain why) If not, can you turn him into a quadrilateral? (Courseware Demonstration)

4. Now that we know the characteristics of quadrilaterals, can you tell us about the objects in our lives. Is the surface also a quadrilateral?

(3) Hands-on operation and acquisition of new knowledge.

1. One point: each group has an envelope containing six shapes: square, rectangle, parallelogram, rhombus, irregular quadrilateral and trapezoid.

(1) Activity suggestions: Work in groups to classify these quadrilaterals. The group leader records the results on the study card and talks about why you classify them this way? (Teacher patrols and guides. When students exchange division methods, the division method of dividing rectangles and squares into one category appears last)

　(2) Possible division methods by students:

① Divided by angles: rectangle, square (all four corners are right angles), rhombus, parallelogram, irregular quadrilateral, trapezoid (no right angles).

② Divided by sides: rectangle, square, parallelogram, rhombus (two sets of opposite sides are equal), trapezoid, irregular quadrilateral (two sets of opposite sides are not equal), rectangle, parallelogram (two sets of opposite sides are equal) ), square, rhombus (four sides are equal), irregular quadrilateral, trapezoid (four sides are not equal).

③ Divided by diagonal: rectangle, square, parallelogram, rhombus (opposite angles are equal), irregular quadrilateral, trapezoid (opposite angles are not equal).

(3) In the process of student points, solve some of the most basic quadrilateral characteristics step by step. (Guide to opposite sides: up and down are one set of opposite sides, left and right are another set of opposite sides)

　2. Further master the characteristics of rectangles and squares.

Let’s look at the way to classify rectangles and squares into one category:

(1) What are the differences between rectangles and squares compared with other quadrilaterals? Talk in the group, maybe using a set square and a ruler.

(2) Group report and draw conclusions. (Post squares and rectangles on the blackboard)

(3) Let’s ask the computer doctor to demonstrate.

(4) Compared with other quadrilaterals, rectangles and squares have certain special characteristics, so rectangles and squares are special quadrilaterals.

(4) (Mobile) Expansion of Application.

1. Who can help me?

(1) is a () shape and a () side shape.

(2) is a () sided polygon with () angles, including () right angles.

(3) There are () quadrilaterals in the picture.

2. Take out a quadrilateral and try it out to see what shape it will become after cutting off one corner.

(5) Class summary.

Today, the teacher and the students learned about quadrilaterals. What did you gain from this class?

Chapter 3 Reflection on the Teaching of "Quadrilateral" in Mathematics "Quadrilateral" for the third grade of primary school. The lesson "Quadrilateral" is a conceptual lesson. At the same time, it is also a highly operational lesson. Students can further understand and consolidate through operations. concept.

The teaching content of this teaching material is arranged as follows:

1. Through students’ existing knowledge and the process of comparison, let students distinguish quadrilaterals from many figures and realize that quadrilaterals have four straight lines. sides and four corners.

2. Let students classify quadrilaterals through observation, measurement, drawing, comparison and other mathematical activities, so as to understand the characteristics of different quadrilaterals.

In this class, what I did better are:

1. Pay attention to life experience and provide perceptual materials.

Most of the world students live in and the things they come into contact with are related to "space and graphics" in mathematics. Life experience is a valuable resource for developing students' spatial concepts. Students have been exposed to many shapes in their lives and are no strangers to quadrilaterals. Therefore, this lesson uses campus scenes that students are familiar with as teaching materials. The purpose is to connect students with their life experiences, enrich their perceptual understanding of graphics, especially quadrilaterals, and perceive the quadrilaterals in their lives as a whole. It not only makes students feel that mathematics comes from life, but also makes them have a strong interest and intimacy in mathematics.

2. Use students’ collective wisdom in the process of group cooperation.

One of the advantages of group cooperation is that students can inspire each other and solve problems from different perspectives. After getting to know the quadrilateral, the teaching session I arranged was a group discussion and asked them to classify the shapes. Here, students' thinking is fully developed, and many situations arise: some are divided based on angles, some are divided based on sides, some are divided based on whether the figures are symmetrical, and some are divided based on whether opposite sides are equal. Especially if the figures are divided according to whether they are symmetrical, students can connect new knowledge with existing knowledge. Although this is the idea of ????a classmate, it has given inspiration to more students. During the discussion, students also developed their speaking and listening abilities, achieving multiple goals with one stone.

In view of the actual reactions of students in the classroom, I feel that there are the following shortcomings, which require continuous efforts:

1. In this teaching, the teaching of the previous links It is the teacher who guides students to acquire knowledge, but in the classification process, students are not given enough time to think and space to express their own opinions, which restricts students' thinking too much, resulting in several good classification methods that cannot be used in the classroom. be displayed on.

2. Faced with the emergence of students, the classroom's ability to cope with it is not strong yet. The students' communication and speeches were relatively active throughout the class, but during the classification process, there was a one-on-one situation between students and teachers. When the student's classification method is exactly what I expect, it seems that the student is just communicating with me. Do the students also understand each other? This is a question worth thinking about.

After the whole class, my feeling is that this class is taught based on students’ existing knowledge of quadrilaterals. Students further understand quadrilaterals during the hands-on operation. Students have a clear understanding of quadrilaterals. I am very interested in dividing, drawing, and piecing together quadrilaterals, and I have a strong interest in learning. However, the teaching process of "classification of quadrilaterals" is not ideal enough. Students can classify intuitively, but it is difficult to express the classification standards in language. In several teachings, students' speech was not ideal.