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The first part teaching material analysis
The textbook "Preliminary Understanding of Fractions" is based on the fact that students have mastered some integer knowledge. From integer to fraction is an extension of the concept of number, which is a qualitative leap for students to understand logarithm. Fractions and integers are quite different in meaning and reading and writing methods.
This lesson is the beginning of the whole unit. A score is not only a score, but also a score unit, which plays a vital role in the understanding, comparison and simple addition and subtraction of scores in the future. Knowing the score is the "core" of the teaching content of this unit.
According to the position and function of the teaching content of this lesson in this unit and the intention of textbook arrangement, I draw up the teaching objectives of this lesson as follows:
Part II Teaching Objectives
1 Have a preliminary understanding of fractions, and be able to understand the meaning of a fraction in combination with specific figures; Can read and write a score; You can intuitively compare the scores.
Through observation, operation, communication and other activities, let students experience the inquiry process of understanding part and understand the meaning of part. Let students gain active experience in mathematics learning.
Through concrete examples, we can feel the extended toolkit of numbers from integers to fractions, experience the application of fractions in life and stimulate students' interest in learning.
The focus and difficulty of teaching: to establish an appearance score.
Teaching key: understand and describe the meaning of a score with concrete figures.
The third part, the design intention.
1 Make full use of the materials provided by textbooks to start teaching.
In this lesson, I take the rich materials provided by the theme map as the starting point of teaching, and the contradictory creative points, the stimulating points of learning interest and the resource points of consolidating practice run through the teaching. For example, in the situation of observing the watermelon theme map in the new lesson, create the demand for scoring; In the example 1, we use the theme map to understand the situation of moon cakes 1/2 and 1/4; In example 2, we use the activity situation of origami to further understand a part; Describe the topic map with scores in the exercise, and apply the scores.
2. Take the extended suite of digital cognition as the main line, so that students can experience the formation process of the meaning of fractions.
In this lesson, I make full use of the materials provided by the theme map of the textbook to continuously stimulate students' curiosity and realize the gradual expansion of the suite from integer to fraction:
First of all, by dividing the moon cakes, you can get a preliminary understanding of the score of 1/2, so that students can understand the logarithm from integer to extended suite to 1/2. On the basis of understanding 1/2, we will continue to classify moon cakes and gradually introduce 1/4. We found that the scores were 1/2 and 1/4. By imagining that moon cakes are divided into five and six portions on average, and each portion can be represented by a score, it is inferred that there are countless scores, and a score model is initially established.
Then, after students further understand 1/4 in the discount, let them discount their favorite scores and get more new scores in the process of "making scores" and communication, so as to verify that there are countless scores.
Finally, in practice, I also consciously arranged an expansion, resulting in several points of the score, paving the way for students to further study the score in the future.
These effective mathematical activities not only let students experience the formation of the concept of fractions, but also let them feel that numbers are constantly expanding their mathematical ideas.
3. Pay attention to hands-on practice, and let students actively construct mathematical knowledge.
In this lesson, I designed colorful mathematical activities such as dividing moon cakes, origami, coloring, finding scores, etc., so that students can realize the transformation from receptive learning to inquiry learning in the operation of dividing, folding, drawing and speaking, and gradually form and intuitively establish mathematical models in operation, comparison, reasoning and communication, and experience a complete process of knowledge construction.
The fourth part is the teaching process.
First, create situations and introduce new lessons.
The theme map of teaching materials is presented by using the characteristics of rich and colorful multimedia, vivid image and changing static into dynamic. Guiding students to observe and describe the obtained information are five small situations related to score learning. Students naturally use integers such as 2, 3, 7 and 8 to describe the number of people, trees and pigeons they see. At this time, the teacher pointed to the watermelon part in the picture and asked the students, "Does every child have a watermelon?" Can you still use numbers like that? Then what numbers should be used to represent its numbers? "When waiting for questions, students' cognition conflicts, and the existing knowledge cannot solve this problem. They are eager to use a new number to express, which lays the foundation for students to understand the logarithmic expansion toolkit. At this time, the teacher reveals the teaching content of this lesson and writes the topic on the blackboard. In this link, the theme map becomes the starting point of teaching and the contradictory creative point. At this time, the teacher reveals the teaching content of this lesson and writes the topic on the blackboard.
Second, participate independently and explore new knowledge.
1/2 Use the theme map to divide the situational teaching of moon cakes. Let's listen to what they are saying when they divide the moon cakes. Guide the students to observe the pictures: First of all, the teacher catches "What do you mean, one person is half?" "How to divide a person into two halves" and other questions make students understand the average score, and use a piece of paper to arbitrarily fold out a counterexample with half big and half small for students to analyze and further understand the average score. It is clear that the average score is the concept that each copy is exactly the same and the size is equal, which lays the foundation for students to establish representative scores. Then the teacher directly pointed out that the bisected part can be represented by 1/2, and learned a new number-fraction, which is the first fraction we know, and then instructed the students to read and write 1/2. Ask the students to talk about the meaning of 1/2 with the help of moon cake pictures. In the activity of dividing and saying, students' understanding of logarithm expanded from integer to 1/2.
1/4 is only 1/2? Continue to observe the moon cake map. This moon cake is divided into four parts on average. Point to one of them and ask questions. Can it still be expressed by 1/2? Why? Ask the students to explain the reasons and try to describe the relationship between this moon cake and the whole moon cake with the new score. With the help of the understanding of 1/2, the whole class deduced 1/4, and at the same time pointed to other pieces and asked, "How much is this piece?" The design of this link enables students to have the first expansion package of comprehension scores: from 1/2 to 1/4.
At this time, students' creativity is affirmed in time, and students are encouraged to try to imagine: if this moon cake is put
When divided into five, six and 10 on average, can one of them still be represented by 1/4? What kind of numbers should be used to express it? At this time, students will have more prototypes in their brains, laying the foundation for understanding other scores.
On page 93 of the textbook, the first question is "Do one thing", and on page 96, practice two groups of basic exercises to further understand the meaning of a score. Let the students see intuitively that no matter what shape a figure is, as long as it is divided equally, each copy is its score.
Teaching example 2
It is a child's nature to be fun and active. After a preliminary understanding of 1/2 and 1/4, ask each student to fold 1/4 with the square paper given by the teacher and show it with colored pens. Then organize students to exchange and show, and guide students to observe and compare several different folding methods: Why are the folding methods different, and each copy is 1/4 of this square paper? Through the process of folding and speaking, students make it clear that as long as the test paper is divided into four parts on average, each part is 1/4, which not only deepens students' understanding of 1/4, but also highlights the essence of the score-average score.
Discount 1/ What
At this time, students know 1/2 and 1/4. Are these the only two scores? In order to let the students know more about the scores, I also designed an activity to let the students talk about it and use the school tools to fold out their favorite scores. This kind of open activity, full of exploration space, enables students to give full play to their autonomy and creativity, actively build mathematical models in hands-on operation, and gain more and more new points in the process of "marking" and communication. The understanding of the score has also risen from the 1/2 and 1/4 extensions to the score.
Three teaching examples 3
In order to let the students know more about the score from the perspective of size comparison, the teacher guides the students to observe and compare the sizes of 1/2 and 1/4 obtained by just dividing the moon cakes with those obtained by feeding pigeons in the trough. With the help of intuition, students can quickly compare the sizes, and through comparison, students can further understand the scores. Guide students to observe and think, and encourage students of different levels to have different experiences and feelings. For example, different objects can represent the same score, and the same object can represent different scores; The more average copies, the less each, the less average copies, the more each. Compare activities, and strive to improve students' understanding of a score from another aspect.
Then show it: the second question of "doing" on page 95 of the basic exercise is completed by the students independently.
After the students basically established the appearance of the score, Cong Cong the elf introduced the history and evolution of the score to the students with multimedia, and infiltrated the mathematical culture thought.
Third, apply new knowledge to solve problems.
After a little understanding, let's take a look at the theme map. What places in the map can be represented by scores?
Let students feel the connection between scores and life and the application of scores in real life. Finally, choose a polygon in the picture and ask the students: Can the colored part in the picture be represented by fractions? This question will undoubtedly conflict with the new knowledge that students have just established? Yes or no? In the dispute between students, the teacher threw out the answer: it can't be expressed by scores, but it can be expressed by scores, which will be what we will continue to learn in the future. This exercise attempts to infiltrate the expansion package with scores ranging from scores to scores.
The fifth part is the blackboard writing design.
The blackboard design of this lesson highlights the process of students' gradual understanding and understanding of fractions, helps students to establish appearances and describe the meaning of fractions.
Ladies and gentlemen, the above is my understanding of the teaching of this course. If there are any shortcomings, please advise. Thank you!