Classification of angles says that the course draft is 1. First, let's talk about teaching material analysis:
"The Classification of Corners" is the content of the third lesson of Unit 2 "Corners" in the first volume of fourth grade mathematics in Jiangsu Education Publishing House. As for the angle, the students have had a preliminary contact in the "Preliminary Understanding of Angle" in Grade Two of Senior High School, and they also have some understanding of the right angle, but most of them are intuitive descriptions. On the basis of the second grade, this lesson summarizes the characteristics of graphics appropriately, and systematically learns the concept, measurement, classification and drawing of angles. It is based on students' initial understanding of angles and the ability to measure angles with protractor to further understand acute angles, right angles, obtuse angles, right angles and rounded corners, and distinguish acute angles, right angles, obtuse angles, right angles and rounded corners according to the degrees of angles. By observing, practicing and exploring the relationship among acute angle, right angle, obtuse angle, right angle and rounded corner, students can feel that the content of mathematics learning is realistic and meaningful, thus experiencing the fun of "learning mathematics" and "doing mathematics".
Second, the student situation analysis:
Students come into contact with many angles of different sizes in daily life, but rarely come into contact with the classification of common angles in knowledge life, which is abstract. Although the abstract thinking of the fourth-grade primary school students has developed to some extent, they still focus on concrete thinking in images, and their ability of analysis, synthesis, induction and generalization is weak, which needs further training.
Third, talk about teaching objectives:
Knowledge goal: proceed from reality and learn about acute angle, right angle, obtuse angle, right angle and rounded corner through interactive learning. Grasp the relationship among acute angle, obtuse angle, right angle, right angle and fillet through observation. And the angles can be classified according to certain standards.
Ability goal: through teaching activities, cultivate students' ability of observation, comparison and abstraction.
Emotional goal: let students experience the exploration process of classification. Experience the fun of cooperation and communication with others, learn to find problems from a mathematical perspective, and cultivate the concept of space.
Teaching emphasis: understand the straight angle and rounded corner, and master the relationship between acute angle, right angle, obtuse angle, straight angle and rounded corner. Guide students to classify diagonally according to a reasonable standard.
Teaching difficulty: fillet is a difficult point in teaching, because fillet is special and the two sides of the corner overlap. In teaching, I take out the activity angle for students to see clearly and rotate it. Then, I summarized the definition of fillet, and asked students to observe the drawing method of fillet, pointing to the vertex and two sides of fillet, so as to make it clear that the two sides of fillet overlap.
Fourth, talk about teaching methods:
1, let students experience the process of mathematical classification, which embodies the process from simple-complex-simple, emphasizes inquiry activities and attaches importance to cooperative learning.
2. Give priority to right angles. Is the angle after the right angle moves inward and outward greater than the right angle? Is it small? The derivation of acute angle and obtuse angle is to highlight the equal dialogue between teachers and students in class.
3. Explore scientific classification through teacher-student interaction by using activity angle. At the same time, the courseware is used to make the two sides of the right angle move to the same straight line, and the two sides overlap, so as to explore the characteristics of the straight angle and the rounded corner, and improve the students' cognitive and thinking level.
Five, said the teaching concept:
In line with the concept of "let the math classroom become the position of students' activities, and let students feel mathematics, experience mathematics and experience mathematics", I have made the following design:
1. Identify the growing point of knowledge and help build the concept.
The classification of angles is the third lesson in this unit. According to the degree of angles, we can distinguish right angles, acute angles, obtuse angles, right angles and rounded corners, and know right angles and rounded corners. So at the beginning of this class, I organized students to review the old knowledge about angles, protractors and how to measure angles, paving the way for further understanding acute angles, obtuse angles, right angles and rounded corners.
2. Work hard on mobility, design teaching activities, provide students with time and space to participate in activities, and help students establish and form the concept of space.
Before this class, the students had a certain understanding of angles, and in addition, they were exposed to many angles in their lives, and learned some knowledge of related angles through various channels. To this end, I am consolidating the exercise part and designing exercises at different levels to let students experience the joy of success.
3. Connect mathematics with life and experience mathematics everywhere in life.
Mathematics learning should be children's own life practice activities, and mathematics teaching should be fully integrated with children's lives, so that students can discover, discover, explore, understand and master mathematics in their own lives. In the teaching of understanding right angles in this class, I ask students to find right angles on the cover, desktop and blackboard of math books. In practice, let students discover real life, such as boxers and rounded corners, which effectively expands the knowledge of textbooks.
Six, the teaching process theory:
Teaching process 1:
By reviewing the names of various parts of the angle, protractor and the method of measuring the angle, I tell the degree of the angle in the courseware, so that students can have a further understanding of the angle and further master the method of measuring the angle. Then ask the question "Can you classify diagonals according to the measured angles?" And introduce a new lesson "classification of angles".
Teaching process 2,
Teach new courses.
Link 1: Know the right angle. I ask the students to take out the rectangular paper prepared before class and fold it with me. Fold up and down first, then fold left and right. Ask the students to observe the angle at which they fold. Ask the students to measure the degree of this angle and tell everyone what degree you measured. So as to obtain a right angle of 90. Then I asked: How many degrees is each corner of the cover of the math book? How many degrees is each corner of the schedule? How many degrees is each corner of the blackboard? What is the angle of a rectangle and a square? Why are they all born after 90? Please point out the right angle on the triangle at the same table. Then I will demonstrate the representation of right angles in the courseware: any angle marked in this way is a right angle. Finally, let the students practice drawing right angles.
Link 2: Know the acute angle. When teaching acute angles, I first demonstrate that the right angle is 90, and then move one side of the right angle inward. Q: Is the teacher moving the angle larger than or smaller than the right angle? After the students answered, I summed it up: then an angle less than 90 like this is called an acute angle. I.e. the acute angle is less than 90. Finally, I asked the students to practice drawing acute angles.
Link 3: Know the obtuse angle. When teaching obtuse angles, I still demonstrate that the right angle is 90 degrees and then move one side of the right angle outward, so that students can observe whether the moved angle is greater than the right angle. Is this smaller? After the students answered, I summed it up: an angle greater than 90 and less than180 is called an obtuse angle. Then let the students practice drawing obtuse angles. After the students know the right angle, acute angle and obtuse angle, I demonstrate the activity angle for students to understand further.
Link 4: Know the Boxer Rebellion. When teaching right angles, I will first demonstrate with the movable angle: move one side of the right angle outward so that both sides of the right angle are on the same straight line. Ask the students to say whether this is an angle. Where is its apex? Where are the two sides? Then I use courseware to demonstrate: a right angle, we move one side outward until both sides are in the same straight line, so we call it a right angle. How many degrees is a right angle? I mainly inspire students to move the right angle into a straight angle, or let them measure it with a protractor, so as to get a straight angle of 180. Then explain the representation of right angles. When teaching the relationship between right angles and right angles, I mainly demonstrate through movable angles: We can move a right angle into a right angle, so how many right angles are there in a right angle? The students' answers are summarized as 1 right angle =2 right angle.
Step 5: Understand the fillet. First of all, let me demonstrate it from the perspective of activities. Let one side of the right angle continue to rotate around the endpoint, so that its two sides coincide. Tell the students that this is also an angle. Let's call it a fillet. Then I will demonstrate the courseware again to deepen students' understanding of rounded corners. When explaining the degree of fillet, I still got the expression of fillet 360 through the demonstration of active angle, and then let the students observe fillet. Finally, by demonstrating the activity angle, let the students tell the relationship between right angle, straight angle and rounded corner. Finally, 1 fillet =2 right angle =4 right angle is obtained.
Link 6: Summarize the content of this lesson, mainly to let students demonstrate several different angles from the perspective of activities. Students think again, talk again and learn again. In this class, I designed four exercises, the contents of which were gradually improved from simple to deep, so that students could sum up the contents of this class in practice and see the mathematics in life in practice, thus generating positive mathematical feelings.
Seven, said the blackboard design:
My design on the blackboard is relatively simple, mainly for students to draw corners on the blackboard and mark the names of each corner.
In short, in this class, I mainly take the right angle as the leading factor and adopt the method of moving, so that students can experience the practical activities of observation, operation and reasoning in a pleasant atmosphere and enjoy the fun of mathematics learning.
Lecture Notes on "Classification of Horn" 2.i. Textbooks
1. teaching content: the first lesson of unit 2, section 1, book 7 of the standard experimental textbook for nine-year compulsory education, that is, the contents of pages 22 to 23 of the textbook.
2. The position and function of teaching materials.
The classification and drawing of angles are based on students' intuitive understanding of acute angles, right angles and obtuse angles and the measurement of angles. Learning these contents plays a very important role in further learning the understanding of space and graphics and developing the concept of space.
3. The compiling characteristics of teaching materials.
(1) Pay attention to learning new content in connection with real life.
(2) On the basis of original knowledge, guide students to construct new knowledge in learning activities.
(3) Pay attention to let students know and master new content through hands-on operation.
4. Teaching objectives.
According to the requirements of curriculum standards and the analysis of teaching materials, and according to the actual level of fourth-grade students, I have determined the following teaching objectives:
Knowledge goal: Through hands-on operation, independent inquiry, group discussion and other activities, make students clear the characteristics of each angle.
Skill goal: You can draw an angle of a specified degree with a protractor, and you can draw an angle of 30 degrees, 45 degrees, 60 degrees and 90 degrees with a triangular ruler.
Emotional goal: make students actively participate in learning activities, gain successful experience, form representations from different angles, and develop spatial concepts.
5. Emphasis and difficulty of teaching.
Defining the characteristics of various angles is the focus of teaching, and how to draw angles with protractor is the difficulty of teaching.
6, teaching AIDS, learning tools
Second, talk about learning.
Before learning the Classification and Drawing of Corners, students have a certain understanding of corners, and some school buildings have been able to classify corners. Therefore, in teaching, students can further master the steps of drawing angles with protractor through their own practical experience, which is much easier for all students to learn.
Third, teaching methods. (omitted)
Fourth, speaking and learning. (omitted)
Fifth, talk about the teaching process.
In order to highlight key points, disperse difficulties and create an autonomous learning atmosphere, I try to fully embody the "student-oriented" teaching concept in the whole teaching process design and design five links.
(1) Introduction of stories and creation of situations.
I introduced it with the story of "rabbits making colorful flags".
(2) Hands-on operation to explore new knowledge.
1, teaching angle classification.
(1) Students intuitively operate and perceive.
Observe and compare the colorful flags made by students, and find that there are different angles and the same size on the flags. (This design is the cornerstone of learning angle classification. )
(2) Ask students to measure the degrees of these angles. Show different angles.
(3) Through observation, find out the characteristics of these angles, and give the names of acute angle, right angle and obtuse angle.
(4) Turn one side of the active angle to guide students to observe and get angles different from these three types of angles: straight angle and rounded angle.
(5) Divergent thinking: Students find out the boxers and rounded corners in life.
(6) Guide students to discover the order of five kinds of angles and the equivalent relationship among right angles, straight angles and rounded corners.
2. The drawing method of teaching angle.
(1) Please draw a 60-degree angle and tell me what tool you used to draw it. Why? Please share your thoughts at the same table.
(2) Ask students to draw an angle of 70 degrees. How to draw? Say the method of painting and correct the mistakes of the local teacher.
(3) The teacher explained that the best way to draw an angle with a specified degree like this is to use a protractor.
(4) Summarize and demonstrate the method of drawing corners.
(5) Students try to draw the angles of rays in different directions, name them and exchange a quantity at the same table.
(3) Apply knowledge to solve problems.
"Apply what you have learned", once new knowledge is formed, it must be applied to solving problems, so as to further form skills and skills. Psychological research shows that the combination of learning and application is an important link to improve and deepen students' knowledge consolidation, so the following exercises are designed: (omitted)
(4) class summary:
What did we learn in this class? How many angles can it be divided into? How to draw an angle of a specified degree with a protractor?
Extracurricular expansion: students collect different angles and compare who finds the most in the next class.
(E) students mutual evaluation, self-evaluation, (mutual evaluation, self-evaluation)
Sixth, talk about blackboard design.
The content of blackboard writing is the essence of a class, which can reflect the teaching content and teaching focus, and reflect the teaching thinking process.
Seven, talk about teaching evaluation.
In the teaching of this class, I boldly organized the teaching materials, with distinct levels, prominent points and scattered difficulties, and always carried out teaching around the teaching objectives. Introduce novelty, create scenarios, let students enter orderly thinking, echo interests from beginning to end, pay attention to students' participation in the whole teaching process, fully reflect students' main role, this class is generous, clear at a glance, and the links are reasonable.