A preliminary understanding of parallelogram: 1 textbook
1. Lecture content: Pages 43-45, Volume II of Grade Four Mathematics, Jiangsu Education Press.
Second, the position, function and significance of teaching content:
This part of the content is to further understand the parallelogram and master its characteristics on the basis that students have initially mastered the characteristics of rectangle, square and triangle, as well as the preliminary understanding of parallelism and intersection. Through the in-depth study of this lesson, it will lay a foundation for students to further understand the area calculation of parallelogram lines in the future. The first example in the textbook first asks students to find out some parallelograms on common objects in connection with real life, and then asks students to fully perceive parallelograms according to their personal life experience. Then let the students make a parallelogram and communicate with each other, and feel the basic characteristics of the parallelogram initially. On this basis, the figure of parallelogram is abstracted to let students know and guide them to explore and discover the basic characteristics of parallelogram. The second example identifies the base and height of a parallelogram and reveals the meaning of the base and height. "Try it" allows students to measure the height and the corresponding bottom surface on the designated bottom surfaces of several parallelograms, and further feel the significance of the height and the bottom surface.
Third, say the goal.
1, knowledge and skills target
(1) Understand the concept and characteristics of parallelogram.
(2) Knowing the base and height of the parallelogram, we can draw the height.
(3) Cultivate students' practical ability, observation ability and analysis ability.
2, process and method objectives
Let the students further accumulate the learning experience of understanding graphics through hands-on operation, eye movement observation, speech expression and brain thinking, learn to make parallelograms in different ways, draw parallelograms on grid paper, correctly judge whether the plane graphics are parallelograms, and measure or draw the height of parallelograms.
3. Emotional attitudes and values goals
Let students feel the close connection between graphics and life, feel the learning value of plane graphics, further develop their interest in "space and graphics" and feel the pleasure of successful exploration.
Four, the teaching emphasis and difficulty:
Teaching emphasis: understanding parallelogram; Make a parallelogram with materials and find its characteristics; You can measure or draw the height of the parallelogram.
Teaching difficulty: students' understanding of the characteristics of parallelogram in the process of making it.
V. Preparation of teaching AIDS and learning tools
Teaching AIDS: triangular, parallelogram paper, rectangular movable frame, small blackboard, etc.
Learning tools: triangle, parallelogram paper, protractor.
Talk about learning.
The fourth-grade students are active in thinking, eager for knowledge and like to use their hands and brains. Have a strong curiosity and desire to explore. Therefore, in teaching, I grasp these characteristics and make them understand what they have learned through eye movement observation, hands-on operation and brain analysis and induction.
Oral English teaching methods and learning methods
In this class, teachers should pay attention to teachers' guidance and students' learning, and ask questions, demonstrate and guide them through teachers. Students use hands-on operation, observation, analysis, discussion, induction and other methods to complete the teaching, so that students can gain new knowledge in a relaxed and happy way. We believe that the teaching of this course should reflect the following points.
First, combine teaching with practice.
"Making mathematics live, and letting students learn realistic mathematics" is one of the new curriculum ideas. In teaching, students should first find the parallelogram from the life scene diagram, and then find the parallelogram in life. Finally, an example is given to illustrate the application of parallelogram deformation in life. Let students feel that "mathematics comes from life and moves towards life". Let the mathematics classroom return to the life world.
Second, let students explore in the activities
Psychologist Piaget said: "Activity is the basis of cognition, and wisdom begins with action." In teaching, students can feel the characteristics of parallelograms by making them and communicating with each other. Let students feel the connection between different plane graphics through activities such as spelling, moving and cutting.
Third, independent thinking and cooperation.
There are two cooperative exchanges in this course. Before the cooperation and exchange, I gave students enough time to think independently, so that they could have nothing to say and their thoughts could collide.
On the Teaching Process
First, create situations to introduce new lessons.
1, introducing jigsaw puzzle
Teacher: Have you ever played Tangram? Do you know what different shapes of jigsaw puzzles are made of?
More than 1000 years ago, people in China invented jigsaw puzzles. Tangram consists of seven figures, which can spell out rich patterns. Foreigners call it "China's Magic Disc". In their view, no intellectual toy is more magical than it.
2. Import: Today we will know one of the figures-parallelogram. (Show the topic)
Design intention: Take the "Tangram" that students like as the starting point to arouse students' learning enthusiasm.
Second, try to explore the establishment of the model
(a) Recognition of an acknowledgement that constitutes an expression
Teacher: The figure here is a parallelogram. After changing the direction, I asked: Is it still a parallelogram?
A parallelogram is a parallelogram no matter how its direction changes. (The picture is posted on the blackboard)
(2) Looking for perceptual features.
1, find the parallelogram in the diagram.
Teacher: Here are some pictures. Can you find a parallelogram on them?
2. Find the parallelogram in life
Teacher: Actually, there are parallelograms around us. Where have you seen parallelogram? (Can be displayed through the camera: removable clothes rack)
(3) Do some distinctive explorations.
1. We just found some parallelograms in our life. Now can you make a parallelogram with the materials at hand?
2. Talk about what you did in the group and choose the representative to report in class.
3. Just now, the students made a parallelogram successfully. Did you find anything or gain in the process? How did you find out? (Group communication)
4, the whole class exchanges, the teacher summarizes the characteristics of parallelogram. (Two groups of opposite sides are parallel and equal respectively; Diagonally equal; The sum of internal angles is 360 degrees. )
Design intention: The new curriculum emphasizes experiential learning. Students should not only think with their brains, but also see with their eyes, listen with their ears, speak with their mouths and do with their hands, that is, experience with their own bodies and feel with their own hearts. Here, students can go through the process from representation to abstraction by knowing parallelogram, finding parallelogram and making parallelogram. Let students feel the characteristics of parallelogram in a series of activities.
(4) practice to consolidate appearances.
Do the questions after thinking 1 and 2.
(5) draw pictures to understand the level.
1. For example. Can you tell the distance between the two red lines of a parallelogram? (Students draw on homemade pictures) Tell me how you measured it.
2. Teacher: The vertical line you just drew is the height of the parallelogram. This opposite side is the base of the parallelogram.
3. What did the parallelogram book say? (Students read books)
4. How many such high-energy paintings are there? Why? Can you draw the height of another group on the opposite side and measure it? (mobile phone)
5. Try teaching. Students measure each other and emphasize the corresponding relationship between bottom and height when communicating.
6. Draw high (think about doing the fifth question) (remind students to draw rectangular marks)
Third, hands-on operation has been consolidated and deepened.
1, think about doing questions 3 and 4 after you finish.
Question 3: Spell it out and move it. Tell me how to move it.
Question 4: Master Zhang, a carpenter, wants to saw a parallelogram board in half to make a rectangular desktop. If you were Master Zhang, what would you think? Want to try it? Try to find a parallelogram paper.
2. Do the sixth question after thinking (do well before class and do activities in class. )
(1) The teacher took out his rectangle, took it sideways and pulled it in the opposite direction. Look what you found. Teachers observe students and communicate with each other.
(2) Judgment: Is a rectangle a parallelogram? Discuss in groups and then explain the reasons. At this time, the teacher can ask the students what kind of parallelogram the rectangle is. What is (special) special?
(3) Obtaining the features of parallelogram.
Then the teacher holds the diagonal of the parallelogram and pushes it inward. Look what you found.
Teacher: Triangle has stability. What do you think of the characteristics of parallelogram through the hands-on operation just now? (unstable, easily deformed)
(4) Application of characteristics
Teacher: parallelogram is easy to deform and has a wide range of applications in life. Can you give some examples? (Students read textbook P45 after giving examples. "Do you know?" )
Design intent:
Fourth, talk about the expansion and extension of harvest.
1, Teacher: Did you get anything from this class today?
2. Use the puzzle in your hand to spell out the figures we have learned.
3. Find the application of parallelogram deformation in life.
Design intent:
Expand the limited space of classroom teaching and combine closely inside and outside the class. After class, students are given practical homework, which requires them to find the application of parallelogram's easy-to-deform characteristics in life, so that students' classroom learning can be linked with after-school life, and students can feel the application of classroom knowledge in life, which can not be separated from mathematics all the time, thus enhancing the intimacy and practicality of mathematics learning.
The teaching goal of the second lecture of "Preliminary Understanding of Parallelogram";
1. Students know the parallelogram in the process of connecting with real life and hands-on operation, find its basic characteristics and know its height.
2. Students further accumulate learning experience in understanding graphics in activities, learn to make parallelograms in different ways, draw parallelograms on grid paper, correctly judge whether plane graphics are parallelograms, and measure or draw the height of parallelograms.
3. Students feel the connection between graphics and life, feel the learning value of plane graphics, and further develop their interest in "space and graphics".
Teaching emphasis: further understanding of parallelogram, finding the basic characteristics of parallelogram, can draw high.
Teaching difficulties: making the height of parallelogram and understanding the corresponding relationship between bottom and height.
Teaching preparation: prepare wooden sticks, nail boards, rulers, triangles, watercolor pens, square paper, colored paper, scissors, parallelogram paper, etc. Group and teach courseware.
Teaching process:
First, the game import
1, talk: game guess map import.
2. In today's lesson, let's further study parallelogram. (blackboard title: understanding parallelogram)
Second, contact with life, a preliminary understanding.
Talk: See where there is a parallelogram in the video. (Stair handrails, electric doors, fences)
Think about it, in our life, which objects have you seen with parallelogram surfaces? (Student example)
Third, the characteristics of students to explore
1. Just now, students have been able to find out some parallelograms in our lives. Can we make a parallelogram by ourselves with some things around us?
2, the teacher patrol, and give some guidance.
3. Which group sent representatives to communicate? Pay attention to show your method, and then talk about the reasons for doing so. Other groups can supplement when they are finished.
Just now, we have been able to make a parallelogram by various methods. Now, please draw a parallelogram independently on the grid paper and think about how to draw it. What should I pay attention to?
We have been able to make a parallelogram in different ways. We can draw a parallelogram on a square piece of paper. So what do these parallelograms of different sizes have in common? According to your experience in making parallelogram, you can guess: What are the characteristics of parallelogram?
6. After the group discussion, ask questions and guess on the blackboard:
The opposite sides may be parallel;
The opposite sides can be equal;
7. Can you find a way to prove whether these conjectures are correct? Students test conjectures in groups.
Thanks to the efforts of the students, we verified this conjecture ourselves. Now let's talk about it. Listen carefully to the speeches of other groups. Are their answers correct? what do you think?
9. The team sends representatives to exchange their own team's verification methods, and other teams will evaluate them after completion.
Finally, the teacher wrote on the blackboard that two groups of opposite sides were parallel and equal.
10, complete "Think about doing 1". Talk about the reasons after students finish independently (courseware)
Fourth, the teaching of the height and bottom of parallelogram
1. Let the students follow the teacher with parallelogram paper in their hands, and the teacher will talk about the folding method while doing it. Then the crease is the height of the parallelogram. (and 44 pages of self-study textbook)
Please draw the height with pen and triangle and mark it. Fold several heights in the same way and observe the characteristics of heights. Then teachers and students write down the definition and characteristics of high and low on the summary board.
4. To complete the "try it": (1) First point out which side the height of a finger is perpendicular to; (2) Measure how many centimeters the base and height of each parallelogram are.
5, think about doing 5, first point to the bottom of the parallelogram, and then draw the height on this bottom, pay attention to draw a right-angle mark. If there are mistakes, let the students say where they are wrong.
Five, practice to improve
1, think about making 2, make a parallelogram with 2 and 4 identical trigonometric rulers, and communicate how to spell it in the group.
2. Think about doing 3. Make a parallelogram with three pieces in a jigsaw puzzle.
Show me, can you move one of them and turn it into a rectangle?
3. Think about doing 4. I want to saw a parallelogram board and make a rectangular desktop as much as possible. Where should I see it? Try to find a parallelogram paper.
4. Think and do 6. Make a rectangle with a beverage tube, then draw it into a parallelogram, and compare the similarities and differences between the rectangle and the parallelogram.
Sixth, reading survey.
Read "Do you know?" Tell me what you have gained, and then look for similar examples in your life.
Seven. Class summary
What kind of plane graphics do we pay attention to today? What are its characteristics? In retrospect, what activities did we learn through?
Lecture Notes on "A Preliminary Understanding of Parallelogram" 3. Textbooks
Lecture content: Jiangsu education publishing house, fourth grade, second volume, 43~45 pages.
Second, the position, function and significance of teaching content.
Understanding parallelogram This course is based on students' intuitive understanding of parallelogram, their preliminary understanding of the characteristics of rectangle, square and triangle, and their understanding of parallelism and intersection. Through a series of exploration and practice activities, they constantly know the characteristics of parallelogram, parallel equilateral, the base and height of parallelogram. This part is the basis of understanding parallelogram area in the future, which is conducive to improving students' practical ability, enhancing students' innovative consciousness and further developing students' interest in "space and graphics".
Third, say the goal.
1, knowledge and skills target
(1) Understand the concept and characteristics of parallelogram.
(2) Knowing the base and height of the parallelogram, we can draw the height.
(3) Cultivate students' practical ability, observation ability and analysis ability.
2, process and method objectives
Let students explore new knowledge through hands-on operation, eye movement observation, verbal expression and brain thinking.
3. Emotional attitudes and values goals
Let students feel the close connection between graphics and life, and feel the joy of successful exploration.
Fourth, talk about the difficulties in teaching.
Key point: Understand the characteristics of parallelogram. Know the base and height of the parallelogram.
Difficulties: Make the height of parallelogram, and understand the corresponding relationship between base and height.
5. Teaching and learning methods.
(A) teaching methods:
According to the characteristics of the textbook of this course, in order to highlight the key points and break through the difficulties more effectively, according to the students' cognitive rules, and following the guiding ideology of "teacher-oriented, student-oriented and training-oriented", the observation and discovery method is adopted as the main method, supplemented by the multimedia demonstration method. In teaching, design inspiring thinking questions, create problem situations and guide students to think. The timely use of audio-visual media in teaching can stimulate students' desire to explore knowledge and gradually draw conclusions, so that students are always in a positive state of actively exploring problems, thus cultivating students' thinking ability.
(2) Speaking and learning methods
1, according to the principle of autonomy and difference, let students participate in the occurrence, development and formation of knowledge independently in the learning process of "observation → guess → generalization → verification → communication → application", so that students can master knowledge.
2. Students can solve more than one problem, guide students to sum up methods in time and overcome the mindset. The example explanation adopts the method of decomposing graphics, so that students can experience and learn the "transformed" mathematical thought.
3. Use the graphics in real life to make the process of acquiring new knowledge natural, enhance students' sense of accomplishment and self-confidence, and thus cultivate a strong interest in learning.
Six, said the preparation of teaching AIDS and learning tools
Teaching AIDS: teaching courseware, triangle, parallelogram paper, rectangular movable frame, nail board,
Learning tools: prepare sticks, rulers, triangles, watercolor pens, square paper, colored paper, scissors, protractor, parallelogram paper, etc. In droves
Seven, talk about the teaching process.
First, guess the map game to stimulate the introduction of interest.
Talk: Students, do you like playing games? Let's play a guessing game.
(Design intention: Through the guessing game, let students initially perceive the characteristics of parallelogram and the difference between rectangle and square, so as to pave the way for subsequent study. )