First of all, talk about textbooks.

Understanding Centimeter is a standard experimental textbook for compulsory education courses, and the first unit of the first volume of senior two mathematics. Through the previous study, students have a preliminary understanding of the comparison of object lengths and compare them through some intuitive objects. This lesson is to teach students to use the basic unit of length "cm" to measure objects. This part is the basis for students to learn the knowledge of meters, millimeters and kilometers in the future. Seems to be the most important thing. First of all, the textbook allows students to experience measuring the same object in different ways, which leads to different measurement results, arouses students' thinking, and embodies the necessity of establishing a unified unit, thus introducing a ruler. Let the students have a look and feel this ruler. Make students change their perceptual knowledge of ruler into rational knowledge, and form a representation of centimeter length through learning activities such as watching, guessing and measuring. Through a series of understanding rulers. Make students understand that shorter objects can be measured in centimeters, and at the same time, they can estimate the length of some objects.

According to the above analysis of teaching materials, I have determined the following teaching objectives:

1, by observing and measuring activities. Let students understand the necessity of establishing a unified length unit.

2. Make students know the unit of length, establish the concept of centimeter length, and learn to measure objects with a scale.

3. Cultivate students' observation ability and operation ability, infiltrate knowledge from practice and apply it to practice. The focus of this lesson is to establish the concept of centimeter length, which can measure the length of an object. Because the abstract thinking ability of senior two students has not yet formed, I think the difficulty of this class is to establish the concept of centimeter.

Bidirectional teaching method

In order to achieve the teaching purpose of this class, in the teaching process, I pay attention to the following three aspects of efforts in teaching methods.

1. Teachers should pay attention to linking knowledge with real life. This will help to stimulate students' interest in learning.

2. In the teaching process, we should focus on the guiding ideology of how to stimulate students to explore new knowledge and improve students' quality in an all-round way.

Knitting teaching.

3, the spirit of mutual communication and cooperation between teachers and students, guide students to carry out mutual evaluation and other activities, consolidate new knowledge, cultivate students' sense of cooperation.

Third, about learning the law.

In the teaching content, try to let students play the spirit of autonomous learning. Look for objects related to the reality of life to measure. Let deskmates cooperate and explore each other in teaching methods, cultivate students' sense of cooperation from an early age, and initially learn to communicate and cooperate with others.

Four teaching procedures

I teach this class in five parts.

The first link: create a scene and introduce a ruler.

According to the courseware, I showed a picture of the ant kingdom. In the picture, a doorpost was broken because the little ant's house was blown away by a gust of wind. The ants want to help the little ants rebuild a gatepost, but they don't know its length. What should they do? Asking this question requires students' help. Tell them that there is a small stick as long as the doorpost on each table. So as to arouse students' thinking, measure sticks with different measuring tools such as thumbtacks, erasers and coins, and exchange the measurement results at the same table. From the different results of students' measurement, a question is raised, why is the length of the same stick different from the measurement results? What if the measurement results are the same? Draw a ruler from it.

The second link is to understand the topic of centimeter derivative.

In this link, the students prepare a ruler to teach. I did five steps:

The first step is to understand the ruler.

Let the students take out the prepared ruler, touch it and have a look. Ask the students what they have found. Tell the students next to you what you found, and then report to the teacher! This problem can reflect students' process of exploring new knowledge and cultivate students' spirit of autonomous learning. It is not difficult for students to find the numbers on the ruler.

Letter centimeters, lines of different lengths. Teachers help students understand the numbers, letters cm and lines of different lengths on the ruler according to their findings.

The second step is the concept of centimeter space, from which we can know centimeter.

Let the students take out the ruler and point. Is the length from there to there on the ruler 1 cm? Help students understand the length of 1 cm by using the elves in the courseware. Have a preliminary understanding of the length of 1 cm. In the small square with the length of 1 cm measured by the students, the teacher instructed the students to hold the small square with their hands and then gently move it away, but their hands could not move. From the length of the small square, it can be understood as 1 cm. Let the students draw the length of 1 cm, and establish the concept of 1 cm through the intuitive feeling of the students' image. In this way, students' understanding is very profound.

The third step is to know how many centimeters by knowing the length unit of centimeters.

Students already know 1 cm through the study just now. So I can draw how much is 0 ~ 2 cm? Why 2 cm? Can you find 2 cm on the ruler? This has successfully realized the transformation of knowledge.

Step four, let students measure the same object and get different measurement methods. The teacher introduced the measurement method.

The fifth step is to help the little ant solve the problem.

Tell the length of the small ant's gatepost through the students' measurement of the stick, so that the small ant's gatepost can be successfully built. The teacher told the students with courseware that the ants were very happy, because you helped the little ant to build the doorpost successfully. It says thank you! Let students understand that helping others is a very happy thing, and cultivate students' helpful personality from an early age! It also cultivates students' interest in learning mathematics.

The third link is to consolidate knowledge through various exercises.

Judgment method: Ask students to raise their hands to judge whether the measurement is right or wrong, whether it starts from 0, whether it is useful to measure with a broken ruler, but it is wrong when reading. These are all mistakes that students are prone to make. Through the training of this topic, it is pointed out that students are easy to make mistakes in measurement, which lays the foundation for further measurement.

Measurement competition: three items are displayed in the courseware, and students cooperate in groups. First, estimate the length of the pencil, then measure the width of the exercise book.

The height of the chalk box is faster and more accurate. Students cooperate in the measurement competition and then feedback the measurement results.

The fourth link: class summary to deepen memory.

Guide the students to recall and summarize: What have you gained in this lesson? How does it help you? How did you do in this class? Wait a minute. This summary helps students to consolidate the focus of this lesson, greatly cultivate their self-confidence and motivate them to learn mathematics better.