The lesson "Comparison of Decimal Size" in the lecture 1 is the content of the unit "Significance and Nature of Decimals" in the second volume of the fourth grade primary school of People's Education Press. I will elaborate from three aspects: teaching material analysis, methods of teaching and learning, and activity process.
Let's start with teaching material analysis.
The content of this lesson is to compare the size of decimals. Comparing the size of decimals is a common problem in students' daily life, and students have certain life experience and knowledge base. This lesson aims to make students have a deeper understanding of decimals, master the comparison methods of decimals, and find and solve problems in interesting mathematical activities.
"Mathematics Curriculum Standard" especially advocates the close connection between what mathematics has learned and the real world. The theme of this unit is a preliminary understanding of decimals, which are related to real life. Based on the understanding of the textbook and the author's intention, according to the basic concept of mathematics curriculum standards, I designed this lesson as follows:
1. Master the method of comparing decimal sizes, and be able to express decimal sizes with symbols.
2. Feel the meaning of decimals, cultivate a sense of numbers, and cultivate the ability to analyze and solve problems.
3. Cultivate the ability to acquire and refine information in activities, improve the awareness of independent learning and cooperative inquiry, experience the close relationship between mathematics and life, and establish confidence in using mathematical knowledge to solve practical problems.
The activity of this lesson focuses on the method of comparing decimal sizes, and the difficulty of the activity is to master the method of comparing decimal sizes skillfully. The preparation materials for the activity include: multimedia, etc.
Second, talk about teaching methods and learning methods.
Mathematics curriculum standard points out: "Mathematics teaching activities must be based on students' cognitive development level and existing knowledge and experience. Teachers should stimulate students' enthusiasm for learning, provide students with opportunities to fully engage in mathematical activities, and help them truly understand and master basic mathematical knowledge and skills, mathematical ideas and methods in the process of independent exploration and cooperation, and gain rich experience in mathematical activities. " Therefore, in the teaching of this class, I start with the students' existing knowledge and experience, tap the mathematical materials in life, boldly explore the learning methods of "mathematical practice activities" and guide students to learn independently. At the same time, I turn the boring math problems in textbooks into vivid practical activities close to students' reality, so that students can feel, experience, understand and master knowledge in the activities and truly become the main body of the activities.
Third, talk about process design.
According to the teaching suggestion of "practical activities" in the mathematics curriculum standard, combined with the actual situation of students, on the basis of analyzing teaching materials and reasonably choosing teaching methods and learning methods, I designed the activity process of this class as follows, including the following four links:
Create a scene and introduce a theme.
Review the introduction and explore new knowledge.
Compare sizes and apply knowledge.
Summarize and review, solve problems
Below I will elaborate on these four activities:
(1) Create a scene and introduce the topic. Male students like the long jump, and the sports group teacher gave the male students a long jump test as an introduction. In view of students' competitive psychological characteristics, the ranking of long jump results has introduced new problems. The design of this link can arouse students' enthusiasm for learning and encourage them to actively participate in learning activities.
(2) Review the introduction and explore new knowledge.
This link mainly introduces the comparison of decimal sizes by reviewing the comparison methods of integer sizes.
(1) Show some exercises for students to answer. Tell me how you compare them.
(2) Summarize the comparison methods of integer sizes.
(3) Compare sizes and apply new knowledge.
The design of this link mainly starts with the common things in students' life, and compares the different prices of four commodities, including three knowledge points, namely, the comparison of integer parts, the comparison of decimal parts and the comparison of percentile parts, so as to sum up the comparison method of decimal sizes. Teachers create a real exploration space for students. Through discussion and communication, students finally get a comparative method, initially feel the close connection between mathematics and life, and experience the joy of successful exploration, thus establishing confidence in learning mathematics well and improving interest in continuing exploration.
Review and solve problems.
This link is mainly to do some exercises and go back to solve the problem of starting design: the ranking of boys' long jump results. This will enable new knowledge to be applied.
At the end of this class, make a summary and ask the students what we learned in this class. The method of comparing the sum of decimals between teachers and students. Guide students to make the final summary and exchange, gradually cultivate students to learn to reflect and summarize the gains and experiences of a lesson, and guide students to think and try to solve real-life problems, so as to enhance the practical value of mathematics learning.
Lecture Notes on "Decimal Size Comparison" 2 I. Textbooks
The teaching content of this lesson is Unit 3, Book 9 of Elementary Mathematics, The Comparison of Decimals, Jiangsu Education Press. The content of this lesson is based on students' initial understanding of the meaning, characteristics and basic properties of decimals. The teaching of this course should start from students' existing life experience, so that students can acquire knowledge through the simple real life situation of buying school supplies, thus improving students' interest in learning mathematics.
Second, the analysis of learning situation
Students have learned "integer size comparison" before. At that time, comparing the size of one or two digits was generally not divorced from the real situation and the specific number, and was limited to integers. On this basis, this lesson is to explore the comparison method of decimal size, which is not limited by decimal places, and also requires students to gradually break away from the specific content and adopt different strategies to compare decimal sizes. This lesson arranges a life situation of "buying school supplies", compares the size of decimals with life experience, and obtains the general method of comparing the sizes of decimals.
In this way, students' enthusiasm for learning is rising day by day, and their ability of autonomous learning is constantly improving.
Third, talk about teaching objectives:
1, knowledge and skills goal: enable students to compare the size of one decimal place and two decimal places, and have specific contents.
2. Process and Method Objective: To cultivate students' awareness of mathematics application and cooperation and communication through activities such as group cooperation and communication; Cultivate students' ability to think and discuss problems in an orderly way.
3. Emotional attitude goal: let students feel the close connection between mathematics and life, stimulate students' interest in exploring mathematics, and gain the joy of success.
Fourth, talk about teaching methods and learning methods.
Situational teaching, in example teaching, creates a learning environment that conforms to students' living situation and guides students to devote themselves to learning.
Learning methods of independent inquiry and cooperative communication. Through observation, comparison and communication, students explore the comparison method of decimal size independently.
Five, the teaching focus and difficulty:
The method of comparing two decimal numbers.
Sixth, the teaching process:
First, the situation import:
Teacher: The new semester has started. All the students need to buy some stationery. Today, the teacher will introduce this stationery store-"Qiqi Stationery Store". Now we ask the salespeople in the stationery store to introduce the prices of the goods to us respectively. Please pay attention and see what you can find.
A classmate acts as a shop assistant and introduces the prices of goods respectively. )
Teacher: After listening to the salesman's introduction, what did you find?
Health 1: This store has exercise books, triangles and other stationery, but the prices are different.
Teacher: What do you think of these findings?
Health 1: Which stationery is more expensive?
Health 2: How much are they worth?
Teacher: Yes, which is more expensive? This is what we are going to learn in this lesson, "Comparison of decimal sizes".
Second, learn new knowledge.
1, explore the method of comparing decimal sizes.
Teacher: Let's guess first. What kind of stationery is cheaper? Think about it, why is this?
Health 1: 0.6 yuan is 6 jiao, 0.48 yuan is 4 jiao 8 fen, 0.6 >; 0.48。
Health 2: 0.6 is 60 0.0 1, 0.48 is 48 0.0 1, 0.6 & gt0.48.
S3: We can see it by converting 0.6 > into a graph. 0.48
Teacher: Great. Everyone is very clever. There are so many ways to think of it!
2. Make a bold guess:
Teacher: Have you learned the comparison of integer sizes before? Remember how integers are compared? (When the integer digits are the same, compare them from the high position; When the number of digits is different, the more digits, the greater the number)
In this link, I give full play to my guiding role: let students recall old knowledge, and further expand the comparison method of integer size to the comparison of decimal size, thus extending and expanding knowledge. Let students become the masters of learning and consciously devote themselves to learning.
The first draft of Comparison of Decimal Size 3.i. Textbook
Educational content
Nine compulsory education six-year primary school mathematics Volume 8 Unit 4 Section 2 Lesson 2 "Comparison of the nature and size of decimals". "Comparison of Decimal Size" includes:
① Comparison of the sizes of decimals with the same decimal places
② Comparison of decimal sizes with different decimal places.
(B) the status of teaching materials
"Comparison of Decimal Size" is a lesson of reasoning and judgment. About "Comparison of Decimal Size" When learning the preliminary understanding of decimals in Volume 7, students have initially learned to compare the sizes of one decimal place and two decimal places. However, the comparison of decimals is basically limited to decimals with the same decimal places and no more than two decimal places at most; The size comparison of different decimal places has never been touched. Through this lesson, students can learn to compare the sizes of decimals with different decimal places, thus further deepening their understanding of the meaning of decimals.
(C) the focus and difficulty of teaching materials
Because further study of "the comparison of decimal size" is the mastery process of students from the comparison of intuitive images to the comparison of abstract thinking, that is, the sublimation of students from perceptual knowledge to rational knowledge, which plays an important role in developing students' analogy ability. Therefore, "the comparison of decimal sizes" is the focus of this section, in which "the comparison of decimal sizes with different decimal places" students often imitate the method of comparing integer sizes, and it is easy to make mistakes by judging decimal sizes only according to decimal places, so it is difficult to explain "the comparison of decimal sizes with different decimal places" in this class.
(D) Teaching objectives
1, so that students can master "the size comparison of decimals with the same decimal places".
2. Make students master the method of "comparing the decimal sizes of different decimal places", and at the same time cultivate students' habit of thinking in order.
Second, oral teaching methods
Combined with the familiar "Yuan, Angle, Minute" and "Long and Short Scale Line Diagram" in students' life, the observation is displayed intuitively, so that students can fully perceive it. Then, through comparison and induction, two kinds of analogy and comparison methods with decimal size are finally summarized, so that students' thinking can gradually transition from image thinking to abstract thinking, and teaching can be organized by using the law of knowledge transfer and the method of inspiration and guidance, so that students can acquire new knowledge step by step in positive thinking.
By using various teaching methods such as intuition, inspiration, discussion, answering first, trying and practice, students are fully mobilized to participate in learning with their brains, mouths, eyes and hands, so as to achieve the purpose of perceiving, summarizing, consolidating and deepening new knowledge.
Third, theoretical study.
Through this teaching, I am letting students master some basic learning methods:
Through observation, comparison and induction, learn to summarize some regular conclusions.
By studying this section, cultivate students' habit of thinking in an orderly way.
By guiding students to read, students' self-study ability is gradually cultivated.
Fourth, talk about the teaching process
This part of the teaching is funded by four levels: ① introducing new lessons with old knowledge; ② Learning new knowledge through intuitive comparison; 3 summary; 4. Consolidate new knowledge.
(1) Review (through slide presentation)
1. Miss Wang brought 300 yuan money to buy a bike. The price of a bicycle is 296 yuan. Did Mr. Wang bring enough money? Let the students say the method of integer ratio.
2. How do you compare the following figures in descending order?
Summary: When the integer digits are different, the one with more digits is larger. When the number of integer digits is the same, compare them from the high place and one by one in numerical order. If the number of one digit is large, that number will be large and will not be compared with the next one.
3. Xiaoming took 14 yuan 80 to the natural selection mall to buy a pen. As a result, he found that the price of a pen was 13.50 yuan. So did Xiaoming bring enough money?
(2) Teaching
We have mastered the comparison of integer sizes: starting from the high position, comparing bit by bit. Today I began to learn "Comparison of Decimal Size". The blackboard writing project then asks the students: Is the method of "decimal size comparison" the same as that of integers, and all of them are compared from high places one by one? The student replied, "Yes". At this time, the teacher deliberately kept silent, leaving suspense, arousing students' desire for knowledge, so that students can enter the best learning state. The teacher took this opportunity to try teaching.