Knowledge target

Understand the meaning of the average score in the actual situation, get a preliminary understanding of the score, read and write a score, and use the score to represent a score of the whole number.

capability goal

Through the process of solving simple problems in real life, students' observation ability, communication ability and cooperative inquiry ability are initially cultivated, which effectively promotes the development of individual thinking.

Affective goal

Let students fully feel the close relationship between mathematics and life, stimulate students' positive and happy mathematical emotions, and make them gain successful experience in solving problems with knowledge.

Emphasis and difficulty in teaching

Teaching focus

(1) Understand the practical significance of the score; (2) Can read and write simple fractions and know the names of fractions.

Teaching difficulties

Understand the practical significance of the score.

training/teaching aid

Multimedia courseware, rectangle, square, circle, equilateral triangle and other graphics.

teaching process

one

Create situations and introduce new lessons.

1, understand 1/2

(1). One point.

Teacher: On Sunday morning, the doorbell of Xiaohong's house rang. As soon as she opened the door, it turned out that the neighbor had come to play. Xiaohong quickly took out something to entertain the little guests. What does she have? If you want to divide the food equally, how should you divide it?

Health: Four apples are divided into two on average, and each apple is divided into two.

Health: Two bottles of mineral water are divided into two parts on average, with each person sharing 1 bottle.

Teacher: A cake is divided into two parts on average. How much is each part? One person gets half the cake. What's the half figure? Students who can write, please write on the blackboard and mark the score. ) In order to accurately represent this half apple, we use "half" in mathematics.

Teacher: This classmate's score is right. I wonder if the students have carefully observed this classmate's writing just now. Do you have anything to say?

Teacher: The customary way of writing is: (Let students write with their fingers empty) Write first, indicating the average score; Write the following 2, indicating that the cake is divided into 2 parts on average; Finally, write 1 above, indicating such 1 copy. Read: Half. Read with the students.

Teacher: Who can tell me what this half means?

Before the teacher demonstrated the action, the students were talking and gesticulating with their hands. )

Teacher: By the way, each serving is half of this cake. Which score can be used to express it?

Teacher: Who will tell me more about this cake?

What does this mean?

Teacher: Just now we used half a cake to show it.

Half, think about it, can you fold half from the paper you prepared?

(Design intent: "Preliminary understanding of the score" must be based on the concept of "average score". Therefore, the first step of teaching is to show the situation of dividing food through multimedia courseware, demonstrate blunt mathematical knowledge with vivid animation effects, and divide four apples, two bottles of mineral water and 1 cake into two parts on average. When assigned to a cake, students find that it can't be represented by an integer that they have learned before. At this time, there is a cognitive conflict between the existing knowledge and experience and practical problems, which makes students have a desire for knowledge. )

(2) 10% discount

Teacher: Then please follow these steps: think, fold, draw and write. The teacher wrote these four steps on the blackboard.

Students operate, teachers patrol and check, choose students' different works and post them on the blackboard. Teacher: (pointing to these works) Please observe. Are they right?

Teacher: (frowning, wondering) Why are half of these papers available in different shapes and sizes?

To show it?

Teacher: (pointing to the first piece of paper) Whose work is this? Please tell me yourself how you express it.

(3) Practice

Teacher: Can this colored part be represented by half? Please judge (courseware shows graphics).

Teacher: (so I see) Oh, I see. Then ask the teacher to help see if this sentence is wrong.

Courseware demonstration: divide a circle into two parts, each part must be half of the circle. )

Teacher: Some students think this is right, while others think it is wrong. Representatives from both sides are invited to debate on stage.

(Design intention: This activity further enriches students' understanding of one fifth, allows students to explore their own conclusions after operating, observing, comparing, analyzing, summarizing and other thinking activities, and at the same time permeates the learning guidance of guessing-verifying-drawing conclusions. The learning style of group cooperation promotes the collision and exchange of different ideas, expands the channels for students to obtain information, cultivates students' good mentality of appreciating others, and promotes the development of students' cooperative consciousness. )

Second, hands-on operation and in-depth learning.

1, learning 1/4

Teacher: Just now, our classmates folded half pieces of paper with different shapes.

Please, can you fold a quarter out of a square piece of paper? Please create a quarter by yourself.

For students, the teacher selects more than three student works, folds them by a quarter with a square and sticks them on the blackboard. )

Teacher: Let's have a look. Are they okay? can use

A quarter to represent it? Then choose a piece of paper and let the students talk about how they make it.

2. Know the names of the parts of the score.

Teacher: We only met half of them and created a quarter.

Do you know the names of the parts in these music scores? Please open your books and learn the names of the parts of the score by yourself.

Teacher: The line in the middle of the score is called the fractional line, which means the average score. The following 2 is called-denominator, which means-divided into 2 parts on average; The above 1 is called-molecule, which means its-1.

Step 3 give it a try

Teacher: We have made clear the meanings of 1/2 and 1/4 through the activities just now. Can you say something like half? Start folding them up? (Student activities, any discount. )

Teacher: Who can tell us about his work?

Conclusion: Through our joint efforts, we know the meaning of the score.

Third, for everyone.

Grading exercise

1, do it

Use the four pictures in the first question of the textbook "Do One thing" to organize students to discuss "how each picture is divided, and the colored part is a score", so as to guide students to describe a score completely and learn to write a score.

Step 2 look for it

Teacher: Actually, there are many such scores in our life. Can you find some? In fact, some scores in life are hidden in things. What scores can you find from these pictures?

Teacher: Just now, the students found so many scores from their lives. There is a school now, and the students are having an outing. Are there any scores we learned today in their activities? Ask the students to help them find it. (Courseware shows the textbook scene)

(Design intention: The new curriculum standard points out that everyone can learn valuable mathematics, everyone can get the necessary mathematics, and different people get different development in mathematics. In teaching, we should pay attention to all students, so that all students' mathematical knowledge, mathematical ability, emotional attitude and so on can be developed, but at the same time, we should also pay attention to students' differences and practice at different levels, so that different people can get different development. )

Third, the class summary

At the end of this class, I sent a famous saying to the whole class by multimedia: "Genius is the inspiration of1100 and the sweat of 99/ 100", which not only expressed my deep blessing to the children, but also experienced the close connection between scores and life.