Teaching objectives:

1. Guide students to get a preliminary understanding of scores in familiar life cases, intuitive graphic and physical discussion and research, establish a preliminary concept of scores, read and write scores, and clarify the meaning of scores with the help of graphics.

2. Compare the molecular score of 1 with the help of objects or intuition.

3. Cultivate students' cooperative consciousness, mathematical thinking and language expression ability through group cooperative learning activities.

4. In the hands-on operation, observation and comparison, cultivate students' courage and self-study spirit, so that they can gain successful experience in using knowledge to solve problems.

Teaching emphases and difficulties:

The preliminary construction of the concept of fraction and some points to be understood. Compare the molecular fraction of 1 by physical objects or intuition.

Teaching philosophy:

The teaching of "fraction" belongs to concept teaching. Concept teaching should pay attention to the process of teaching activities, that is, the teaching of thinking activities in the teaching field, not just the result of mathematical activities-the teaching of mathematical knowledge. Its occurrence and development have a process. Only by letting students know the "ins and outs" of scores can learning be full of interest and motivation. In the teaching design of this course, I tried to make several attempts:

First of all, create rich mathematics learning situations to help students learn scores.

From integer to fraction, it is a cognitive breakthrough for students. In order to build a breakthrough stage for students, I have designed a wealth of realistic situations that are close to students' reality and are of interest to students, such as "dividing moon cakes". On the basis of highlighting the average score, I help students understand and understand the meaning of scores in familiar situations, thus introducing new lessons. Students experience the generation process of time markers in positive thinking and trying, and initially perceive the concept of time markers under the guidance of teachers.

Second, strengthen mathematical practice activities, so that students can actively construct mathematical knowledge.

Students' learning of mathematics knowledge is not passive acceptance, but active construction, and hands-on operation has a positive role in promoting students' construction. Therefore, in this class, I fully provide students with opportunities to practice, and let students understand the meaning of scores in the process of hands-on, brains and mouth-opening through the situation of "folding and folding". For example, when you know the score, ask students to fold out one-half and one-quarter of a square piece of paper to further understand the meaning of the score.

Third, innovative exercises make concept learning open to a certain extent.

Concept learning is not boring, and the charm of scores can make concept learning open to some extent. Therefore, I designed activities such as finding scores from graphs, comparing scores by origami and comparing scores by graphs, which not only permeated the idea of combining numbers with shapes, but also helped students understand the connection between scores and life and experience the happiness brought by successful learning.

Teaching process:

First, create a situation, set doubts and stimulate interest, and experience the process of generating scores.

1, wonderful introduction

The teacher took out four moon cakes and asked the students to help the teacher think about it. If these four mooncakes are given to two students, how should they be distributed fairly? How much does everyone get? Give two pieces to two people. How can we divide it fairly? Give a piece to two students. How to divide it fairly? (The teacher demonstrates how to divide the mooncakes), which leads to the new lesson "Divide". Teacher's blackboard "score.

2. Writing and reading of teaching scores

(1), write the score.

The teacher demonstrated the process of dividing moon cakes. (Emphasis on average score) How to express half by score? Divide the moon cake of 1 into two parts on average, where 1 is 1/2 of this moon cake. (Teaching Writing Score "1/2")

Teacher: Just now we know the score "1/2", and each part of the score has its own name. Taking "1/2" as an example, the teacher summed up the meaning and wrote on the blackboard:

Teacher: Please raise your right hand and read after the teacher: First, draw a short horizontal line to indicate the average score. This line is called the fractional line. (The teacher said while writing on the blackboard) Divide it into two parts on average and write "2" at the bottom of the score line. We call it the denominator (the teacher's blackboard book). Everyone gets two parts of 1 copy and writes "1" on the score line. It's called a molecule. (Teacher writes on the blackboard)

1 ...

-... the score line says: half.

2 ... denominator

2, born on the table, the writing of "half" is empty. Tell each other the names of each part of the score at the same table.

3. The teacher should write the fractional line first, then the denominator, and finally the numerator. When reading fractions, read the denominator first, then the numerator. Students read together. Students practice speaking and writing, and the teacher says several scores at the same time. The students write them in their exercise books and instruct them to perform.

(4) Practice of saying the name of the music score and reading the music score: The teacher shows the music score, says the names of each part, and reads the music score.

(Design intention: This link is mainly to let students start from the existing knowledge and experience, as well as the practical significance of the score. Through the introduction of the daily life situation of "dividing moon cakes", students draw the conclusion that "a moon cake" is divided into two parts on average, and each person gets half. With the help of physical demonstration, the "half" is abstracted from a specific quantity to a number, and the concept of score is preliminarily understood to establish a new cognitive balance. At the same time, on the basis of students' understanding of music score, the names of various parts of music score are introduced to further guide students to understand the meaning of music score. )

Second, strengthen mathematical practice activities and let students construct mathematical concepts independently.

1, half done

① Take a square piece of paper, fold out its 1/2 and color it. (Life and death teachers patrol)

(2) The report shows that

(3) Solve the question "What can 1/2 represent for colored parts with different folding modes?" problem

Reports and presentations.

2. Exercise: Can the colored part in the picture below be represented by half? Explain why. (Multimedia demonstration) Students' exercises

3. Students associate a quarter of the new scores with half of their studies. (A quarter of the teacher's blackboard) If we continue to divide the square equally, how many more may appear?

Correlate and report

(Design intention: This link is mainly for students to initially establish half of the concepts and representations. Guide students to grasp the essence and make a moderate abstract summary. "As long as the object or figure is divided into two parts on average, 1 is half." Then, it further moved Lenovo by one-fifth, one-sixth, one-seventh, one-eighth and one-tenth ... It subtly guided students to think deeply and effectively cultivated their abstract thinking ability. )

4, hands-on fold a quarter

(1), students take a square piece of paper, fold out a quarter of this paper and color it with your favorite color. After folding, let's talk in the group and see if there are different folding methods. (Life and death teachers patrol)

(2) Exchange report

③ Solution: "Look carefully at the different folding ways of these figures. Why are all the colored parts represented by a quarter? " problem (Student answers)

(4) The teacher summarizes the same figure and expresses the same score with different folding methods.

(Design intention: This link is mainly to let students know more scores independently, and transfer and expand their knowledge appropriately through independent thinking, hands-on operation and group communication. Students show the formation process of knowledge from their respective interests, needs and cognitive starting points. Under the question of "Why can different folding methods be expressed by a quarter", guide students to gradually understand that the different folding methods are not the essential attributes of music scores, but the essential attributes of music scores are "how many copies are divided equally" and "only one copy can be used to express this 1 share". )

5. Compare scores.

1. Take out the square that has just been folded, and compare it with one-half and one-quarter. Whoever is bigger is smaller. Compare the folded pictures in your hand and tell the reason in the group. (health report)

2. Teacher's summary: the molecule is 1. The method of comparing scores: "The numerator of a score is 1, and the larger the denominator, the smaller the score; The smaller the denominator, the greater the score. "

(Design intention: This link is mainly to explore the score as the attribute of numbers and compare the scores intuitively. Guide students to organically combine operational activities with language expression and developing thinking, compare the scores expressed by students, skillfully use the generated learning resources, and deepen their understanding of the scores through comparison. )

Third, consolidate the application and deepen the understanding and application of the meaning of fractions.

1, the courseware shows a five-pointed star and a windmill. What grades do these things remind you of? answer

2. Courseware display book 1, 93 pages with 2 questions, 96 pages with 3 questions, which the students completed independently. (Teachers and students * * * revise together)

3. Let the students talk about what things around them have found the shadow of the score. (Student answers)

4. Teacher's summary: The students talked a lot. Yes, scores are everywhere in our lives and are closely related to our lives. In today's class, we have got to know each other a little. In the future study, we will continue to approach the music score, understand the music score and explore more mysteries about the music score.