People's education printing plate elementary school third grade mathematics first volume.

Understanding of the first volume of mathematics in the third grade of primary school published by People's Education Press

I. teaching material analysis

The knowledge of kilometers is the content of pages 84 and 85 of the fifth volume of mathematics in six-year primary schools with nine-year compulsory education. The understanding of kilometers is an important content of mathematics quantity and measurement knowledge in primary schools. It is taught on the basis that students have learned the length units such as meter, decimeter, centimeter and millimeter, and have a preliminary understanding of the application of these length units in daily life.

The outline clearly points out: "We should pay attention to learning and understanding mathematics from students' life experience and existing knowledge". Because students rarely have access to kilometers in real life, students feel abstract and it is difficult to establish the concept of 1 kilometer. So I think the focus of this lesson is to let students establish the concept of kilometers, and it is very difficult to estimate the length of objects correctly on the basis of establishing the concept of kilometers. In order to highlight the key points and break through the difficulties, the key to teaching is to contact students' real life as much as possible and increase their perceptual knowledge of this kilometer.

According to the characteristics of teaching materials and the age characteristics of students, I have formulated the following three teaching objectives:

1, knowledge goal: let students know the unit kilometer, establish the concept of 1 kilometer, remember 1 kilometer = 1000 meters, and carry out simple aggregation.

2. Ability goal: in the process of understanding kilometers, cultivate students' ability of observation, comparison, abstraction and generalization, and accurately estimate the length of objects with kilometers.

3. Emotional goal: Through group cooperation and communication, let students get a successful experience in the process of exploration and cooperation.

The schedule of this class is 1 class hour.

Second, oral teaching methods

The subject of teaching is students, so I analyzed the situation of students. Because the students have learned the meters, decimeters, centimeters, millimeters and other length units, and the third-grade students have the initial life experience of perceiving the length, they have made full preparations in basic knowledge and skills. However, the third grade students are used to thinking in images, and it is still difficult to establish the concept of length as large as 1 km. The lack of in-depth understanding of the length unit kilometer will inevitably lead to improper use of the weight unit and inaccurate estimation of the length of the object. Due to the characteristics of students' thinking development, I adopted the methods of observation, experiment and practice, and established the connection between what I have learned and my practical experience in life. This way of learning allows students to learn knowledge through personal experience and let them feel that mathematics is in our lives.

Third, theoretical study.

To be a "good teacher", teachers must guide students in learning methods, because "methods are the key to opening a treasure house of knowledge". Learning instruction, like teaching method, must be optimized according to students' characteristics and learning content. In the group experiment, guide them to learn the thinking methods of observation, comparison, analysis, abstraction and generalization; Learn to cooperate and discuss; When they know the kilometers, guide them to learn to teach themselves and summarize.

Fourth, talk about teaching procedures.

(a) review of imports

1 How long is one meter?

2. Show the meter ruler and let the students talk about its function.

3. When we measure the width of the math textbook and the thickness of the pencil box, do we still measure it in meters? When the meter ruler is too long to measure these objects, we introduce length units smaller than meters, such as decimeter, centimeter and millimeter. What is the relationship between these units?

4. How far is it from wudan Town Central Primary School to Wenzhou Zoo? Can you do something? According to the students' answers, when measuring the length of the journey, we usually use the unit kilometer (blackboard writing topic) which is larger than the meter. Now let's meet the kilometer.

(This import method is based on students' existing knowledge. By cleverly setting questions and suspense, students are encouraged to actively explore new knowledge and understand the role of kilometer units. )

(B) the new curriculum teaching

1, know kilometers

(1) Yes,10m.

Measure 10 meter with a tape measure on the school playground, and insert two javelins at both ends to let the students take a walk and have a look. Then move the javelin every 10 meter. At the same time, let students observe, walk and understand dozens of meters. For example, what object is about 10 meter long?

(2) Know 100m. Through measurement, 10 10 meter is 100 meter. Observe, and then walk and think about the length of 100 meters. For example, the length from where to where is about 100 meters.

(3) Know1000 m.

A few days before this class, the PE teacher has used physical education class to organize students to run around the playground track for four times, and everyone must finish it. It doesn't matter if they run slowly. Students talk about the feeling of running first, and then tell them that the runway is 250 meters. How many meters did they actually run?

2. Aggregation between units.

(1) 1 000m is1km, and1km is1000m (blackboard km, meter relation).

Kilometers are sometimes called kilometers.

(I ran the arduous 1km through personal experience in connection with real life. At this time, the "kilometer" has left a deep impression on students' minds, which will be a long time and break through the difficulty of establishing the concept of 1 kilometer. )

(2) Teaching examples 1

We have studied the reciprocity of meters, decimeters, centimeters and millimeters before. Now can you solve this problem by yourself according to 1km = 1000m? Please have a try. Students who have difficulties can discuss it with their deskmates.

Calculate 2 kilometers = () meters

Students calculate the results and then say what they think.

Practice again:

2 km 500 m = () m

6 km 30 m = () m

Talk about ideas after practice.

(3) Teaching Example 2

Try to practice.

4000m = () km

And talk about the basis of the practice process?

Practice again

10000m = () km

Try to practice:

4350m = () km () m

Think about it: 4000 meters is 4 kilometers, 4350 kilometers is 4 kilometers, 530 meters.

(4) Give it a try:

6 km 720 m = () m

5830 meters = () meters

3. Summarize the length unit.

After learning this unit, we have learned all the length units. You can draw the length of each length unit (except kilometers) by hand first. Who can rank them from small to large?

A: We learned five units of length * * *, which are arranged in descending order: millimeter, centimeter, decimeter, meter and kilometer.

Are the forward speeds between adjacent length units the same? What is the difference?

A: There are four basic formulas for forward speed, namely:

1 km = 1000 m, 1 m =1decimeter1decimeter = 10 cm, 1 cm = 10 mm.

On this basis, the following ratio relationship can be calculated:

1 km = 10000 decimeter = 100000 cm = 100000 mm.

1 m = 100 cm = 1000 mm

1 decimeter = 100 mm

(Guide students to sort out and summarize the length units they have learned and their progress, so that students can understand a complete knowledge system of length units. )

Summary: What have you gained today? What other questions are there? How did you learn this knowledge?

Third, consolidate the application

What problems do you think can be solved after learning this knowledge?

There are so many practical problems, you can choose your favorite problems and try to solve them after class. The teacher here also collected several questions. Can you solve them with the skills you learned today?

1, fill in the appropriate length unit.

A tug-of-war rope is 12 ()

Xiaodong's shoulder width is 30 ()

A car travels 60 miles an hour.

A math book is 8 ()

The distance from Beijing to Wenzhou is 25 10 ()

The distance from Hangzhou to Wenzhou is 367 ()

The distance from the school to Wenzhou Zoo is 12 ().

This problem is most closely related to life. It can strengthen students' comparison between kilometers and meters, decimeters, centimeters, millimeters and other length units, and cultivate students' ability to use length units accurately. )

2. fill in ">", "

( 1)5km◎678m； (2)28 mm 6 cm;

(3) 100 decimeter ○ 10 meter (4)6 decimeter ○485 mm

3. There are four kinds of objects, A, B, C and D, and their lengths are as follows. Then the longest object is ().

A, 680mm b, 4mm c, 2mm d, 216cm

The purpose of arranging this question is to carry out unit conversion and size comparison on the basis of students' mastery of length units. The concept of actual length is established by choosing an appropriate quantity. )

4. Can you give some concrete examples?

(1) An object about 6 decimeters long (give 5 examples).

(2) Kilometers is the most suitable unit (give five examples).

On the basis of mastering length units skillfully, I will use what I have learned to solve application problems, and I can use real-life examples to improve my ability to use length units. )

Blackboard design:

Knowledge of kilometers (kilometers)

Millimeter, centimeter, decimeter, meter, kilometer

1 km =1000m

1 m = 1 decimeter 1 decimeter =10cm,1cm =10mm.

Example 1:

(1) 2km = () m

(2)2 km 500 m = () m.

Example 2:

(1) 4000m = () km

(2) 4350m = () km () m。

This blackboard writing design is conducive to guiding students to observe and summarize abstractly; Second, the blackboard design and teaching ideas are harmonious and unified, which can present the knowledge points of this lesson concisely and prominently, and it seems clear at a glance.