Tisch
Teaching material analysis: In the textbook design of this lesson, grid paper is mainly used as a carrier to assist students to compare the sizes of different shapes of graphics independently, and there are many ways to compare the sizes of two graphics. Analysis of learning situation: because the students in my class have poor hands-on ability, they didn't have much foundation before. Although I have been training for one academic year, I am still not satisfied. So design a teaching link: students take "Do you want to know the area of each figure? How do you know their area? " Operate independently first, then communicate with the group and focus on different solutions within the group. Then the whole class reports in groups.
Teaching objectives:
1, with the help of grid paper, you can directly judge the size of the graphics area.
2, through communication, know the basic method of comparing the size of graphics area.
3. Experience the relationship between the change of graphic shape and the change of area.
Teachers should pay attention to cultivating consciousness: observation, comparison, independent thinking, operation, communication, knowledge and methods go hand in hand.
Teaching emphasis: area comparison method.
Teaching difficulty: equal product transformation of graphics.
Teaching process:
First, the new curriculum teaching
1, the method of comparing graphic area (showing wall chart)
1. Find a picture: What picture do you see?
(2) Let the students operate with this problem.
(Open the bag of learning tools and compare it with the figure matched with the wall chart) (Triangle, parallelogram, trapezoid, rectangle, irregular figure. )
Question: Do you want to know the area of each figure? How do you know their area?
(counting squares)
2. Request activity: Now please count the area of each graph.
Default: (1) Get the graphic area by calculating the grid.
(2) What should I do if I can't count the squares?
(Bring it up for discussion, or pick out figures that can be squared. )
(3) There may be some students who can get the graphic area by different methods.
Self-concern: In the textbook, grid paper is used as the carrier to present various shapes of plane graphics. Comparing the size of graphic area with square is to prepare for learning how to find the graphic area without square.
(4) Reporting and communication: How do you know?
①4.5 ②6 ③4.5 ④9 ⑤6 ⑥6 ⑦9 ⑧ 12 ⑨4.5 ⑩ 10.5( 1 1) 15 ( 12) 15( 13) 15
3. Compare the sizes of graphic areas.
(1) Classify the graphs with similar areas, and let the students compare the sizes of the graphs in groups.
Put forward operational requirements: how do you want to compare?
(patrol to understand the activities, individual guidance, and find most students' problems. )
(3) After the group activities, the students communicate with each other. (Mainly to exchange experiences with each other,)
1=3 2=5=6 5+6=8 1+3=4=7 9+ 10= 1 1= 12= 13
(4) Thinking: How do you know?
When students report, they should be instructed to explain the methods and operating procedures they found. )
Personal attention: students summarize and sort out the methods of comparing the area of plane graphics. Then the whole class reports on behalf of the group. After one group has said it, the other groups will add it, and they can show it while reporting. When reporting, team members can cooperate.
I want to predict the possible results: that is, I want to know several teaching plans, but at this time students may only report the ones suggested in the book. At this time, students will be guided to summarize several reports, and it is not necessary to summarize each one. The evaluation should be carried out randomly according to the report.
The purpose of this link is to let students compare the areas of different graphs according to their own experience, and master some comparison methods through the comparison of graph areas. )
Third, consolidate the exercise (complete the tasks shown in the figure below)
1, can you use your own induction to determine which of the following graphs are the same as the figure 1 area?
How did you know?
(The first exercise focuses on segmentation and translation. )
Personal attention: If students don't have this method in the first link, they should guide induction and make up for it at this time. Mainly to let students understand that the area of the figure has not changed. If the region has not changed, why do you need to divide and translate? Prove that experience is the purpose, but we should realize that the area of graphic change is constant = equal area deformation. Infiltrate a mathematical thought, lay the foundation for the derivation of the formula of learning area in the future, and have the thinking habit of solving problems. You don't have to give students a concept, just know it, and the teacher can understand it himself, mainly to pave the way for the calculation of the area after students study.
2. Which of the following figures do you think will complete this figure? Why?
Let the students discuss which figure to fill in and cultivate their observation ability. )
3. Students, think carefully: If the area of each small square in the grid diagram below represents one square centimeter, can you draw three different figures with an area of 12 square centimeter?
Try with the square paper in your hand.
Draw a picture according to your own understanding, as long as the area is 12 square centimeter. )
(1) Independent operation
(patrol inspection to understand the existing problems and students' completion. During the tour, we should pay attention to the selection of representative works for display. )
(2) Class communication-
Personal concern: I think this drawing problem is more important. I can give you a hint if the students draw simply. The figures drawn by students in this learning activity do not need to be classified, as long as students are encouraged to draw other figures besides rectangles as much as possible to experience equal-area deformation.
Take out two numbers in the schoolbag. Please try which figure they can spell.
(1) Independent operation
(2) Communication and demonstration
(3) Expand: Can you still use these two figures to make a new figure?
(4) Independent operation
(5) Stick the communication demonstration on the blackboard.
Sublimation of ability: Did you find anything valuable for mathematical thinking through the activities just now?
The students concluded that the shapes of the figures are different, but their areas are all equal.
Or combined with practical examples in life: for example, in decoration, many patterns on the floor or wall are formed by equal volume deformation, so as to make this road close to life and let students become designers. (This link depends)
Personal attention: students should go down to the group to guide students and understand their situation. Most people's problems are solved by the collective and individuals on the spot, and it is not necessary for teachers to solve them. Ask your classmates to help you solve it and try your best to solve it.
extreme
Teaching content: Compare the areas of graphs.
Target preset:
With the help of grid paper, the size of graphic area can be directly judged.
Through communication, know the basic method of comparing the size of graphics area.
Experience the relationship between the change of graphic shape and the change of area.
Teaching emphasis: area comparison method.
Teaching difficulty: equal product transformation of graphics.
Teaching process:
First, the new curriculum teaching
Method for comparing the sizes of graphic regions
Ask students to observe the plan of various shapes in the grid;
Question: What is the relationship between the areas of the following figures?
How did you know?
Student exchange.
Second, induction and comparison:
(1) Translation (2) Division (3) Number of squares
What else did you find? Communicate with classmates
Third, practice.
1. Use segmentation and translation methods for judgment.
2. Draw according to your own understanding, as long as the area is 12 square centimeter.
3. Ask students to discuss and observe which picture is suitable for filling.
Fourth, homework
Class assignment:/kloc-question 4 on page 0/7.
Homework: Draw a figure with an area of 24 square centimeters on square paper.
Teaching reflection
Guided by the new teaching concept, based on the characteristics of the discipline system and students' cognitive rules, the comparative graphics regional course is integrated with computer information technology, and adopts the methods of independent inquiry, cooperative exchange and multimedia demonstration and verification. So that every student can actively participate in teaching activities. The main task of this lesson is to let students master the method of comparing the size of graphics. According to their own knowledge and cognitive level, each student has a discussion in the form of group activities after full independent thinking and exploration, so that students can master the comparative method in independent exploration, which reflects the diversity of methods. Cultivate and develop students' concept of space.
I designed the teaching material, which consists of three teaching links: speaking, thinking, practicing and practicing. The key point is thinking, so that students can master the method of comparing the size of graphic area and understand the relationship between the change of graphic shape and the size of graphic area. Therefore, when dealing with this link, I introduce the theme with relaxed topics and mobilize students' exploration through multimedia courseware. Timely guide students to discover the relationship between the five graphic areas on the big screen, and explore the method of comparing the graphic areas. Research and solve new problems with the help of students' existing mathematical knowledge. Help students form a certain autonomous learning ability. It paves the way for exploring the relationship between the areas of 13 subgraphs in the main picture of the textbook. Psychologist Bruner believes that learning is an active process. The internal motivation of students' learning is to arouse students' interest in the materials they have learned, that is, the internal motivation from the learning activity itself, which is a psychological motivation to directly promote students' active learning, so I use multimedia courseware to show the main picture of the textbook and stimulate students' inquiry. When 13 pictures of the main picture of the textbook appear on the big screen in the form of multimedia courseware, the vivid image of multimedia courseware attracts students and opens their eyes. Search hard, eager to discover more mysteries, and put forward guiding suggestions in time. It is required to observe and judge the relationship between graphic areas first, then use learning tools to verify and make records for communication. The purpose is to seize every opportunity to cultivate and train students' mathematical thinking. After each student's whole brain observation and hands-on autonomous learning. Through group cooperation and communication, students can master the method of comparing the sizes of graphics, and further realize that the shapes of graphics are different, but the areas are all equal. When reporting and communicating with the whole class, students should pay attention to all students and show them as many opportunities as possible to build self-confidence. Ask students to talk about how they compare themselves and what their basis is. When they find that students' comparison methods are unique, they should encourage them in time, fully mobilize students' learning enthusiasm and enhance their self-confidence. At the same time, they also set up a platform for students to show themselves, reflecting the diversity of graphic size comparison methods. Students truly become the masters of learning and their personalities are fully developed. When I use multimedia courseware to demonstrate and verify the students' findings one by one, the students stare at the big screen and hold their breath, waiting for their findings and methods to be confirmed. At the same time, all students have experienced the whole process of discovering and comparing methods, and their perceptual knowledge has also been improved. In practice, I let students use their own methods to solve practical problems. Through the process of students' hands-on operation, we can understand the method of area comparison more clearly and understand the relationship between graphic change and area size. The whole teaching process fully embodies the important role of computer information technology in primary school mathematics teaching, and its intuitive demonstration conforms to the thinking activities of primary school students with image thinking as the main part. Its image and vividness attracted the attention of every student. From the bottom of my heart, I have a kind of curiosity and exploration. Students are full of interest in learning and the classroom atmosphere is active.
There are also many shortcomings in the teaching process. For example, when practicing, the practice lacks depth. If practice can be deepened, the purpose of practice can be highlighted. It can also provide another learning opportunity for students who have not mastered it. In short, in the future teaching, we should strive to improve our adaptability and do a better job in teaching.