Primary School Mathematics "Understanding of Decimeters, Centimeters and Millimeters" Lesson Notes

Primary School Mathematics "Understanding of Decimeters, Centimeters and Millimeters" Lecture Notes

1. Teaching Materials

1. Analysis of Teaching Materials : This lesson is the content of the third unit of the fourth volume of the primary school mathematics compulsory textbook. It is taught on the basis of students' understanding of the unit of length, so that students can further deepen their understanding of the unit of length and prepare students for further learning of the unit of length in the future. Lay the foundation for the aggregation of space and other geometric knowledge. The textbook first introduces new units of length by asking students to use a meter ruler to measure the length of the blackboard, and then uses methods such as recognizing, measuring, taking a look, and thinking about it to help students recognize these units of length and understand two adjacent units. Progress rate between units. The arrangement of the exercises is as follows: T1, 2, 3, and 6 are practical questions to enable students to master the measurement method, and T4 is to fill in the measurement units. T5 is the conversion between decimeters, centimeters, and millimeters to consolidate the rate of progress between units.

2. Based on the layout intention of the teaching materials and the actual situation of the students, I determined the teaching objectives of this lesson based on the concept of the new curriculum and starting from the aspects of knowledge and skills, mathematical thinking, problem solving and emotional attitude. For:

(1) Let students understand decimeters, centimeters and millimeters in practical activities; establish the correct representation of decimeters, centimeters and millimeters.

(2) Let students learn to choose appropriate length units and understand the progression rate between length units during the actual measurement process.

(3) Let students improve their awareness and ability to participate in learning during activities and form some basic strategies for solving problems.

(4) Let students experience the close connection between mathematics and real life, and cultivate students’ awareness of estimation and cooperation.

3. The focus and difficulty of teaching in this lesson are to enable students to establish specific concepts of decimeters, centimeters, and millimeters.

4. Teaching key: Through practical operations, let students participate in activities such as recognizing, measuring, taking a look, thinking about, and finding, etc., to help students establish the decimeter, centimeter, and millimeter specific concepts.

5. According to the characteristics of this lesson, in order to make the teaching proceed smoothly, the teaching aids need to be multimedia courseware. The learning aids need to prepare a large number of physical objects, such as: thumbtacks, pencils, leaves, ropes, etc. Notes, coins, etc.

2. Preaching and learning.

“The most fundamental thing about optimizing the teaching process is to guide students to actively participate in the learning process, learn to learn, and make them truly the masters of learning.” Based on this concept, I have made great efforts in teaching and learning methods. This is how I envisioned it:

Throughout the teaching process, I aim to abandon the teaching that is full of classroom teaching, strive to develop intelligence and cultivate abilities throughout, and use a variety of teaching methods such as observation, operation, discussion, and induction. , concretizing and visualizing abstract knowledge. In teaching, I accurately grasp the level and depth of knowledge, and allow students to actively participate and explore independently. Through practical activities such as recognizing, measuring, taking a look, and thinking about it, students can devote themselves wholeheartedly to teaching. process, thereby understanding the specific concept of length units.

3. Teaching program design.

In line with the quality-oriented education classroom concept of "development as the purpose, students as the main body, teachers as the leader, and teaching materials as the main source", I specially designed practical operations, using the old to introduce the new; independent Explore and learn new knowledge; summarize the whole lesson, review and organize; comprehensively apply, deepen and consolidate; "teaching at four levels. In teaching, we strive to reflect that "students are the masters of learning, and teachers are only the organizers, guides, and collaborators of learning" "The concept of this new course.

Let’s talk about the first level first, practical operation, using the old to introduce the new.

Arrange two links: 1. Review the unit of length, meters. Deskmates Cooperate to cut a 1-meter-long rope.

2. Ask students to use this 1-meter-long rope to measure the length of the pencil. What do you think? This will arouse students' strong desire to learn new length units.

(Because old knowledge is the basis of new knowledge, and new knowledge is the extension and development of old knowledge. With this design, old knowledge creates conditions for the learning of new knowledge. On the one hand, the meter is reviewed by cutting a 1-meter-long rope, and on the other hand, the old knowledge is the basis for the new knowledge. On the one hand, it provides intuitive materials for the following specific concepts of establishing four units of length, and arranges to use a 1-meter-long rope to measure the length of a pencil, which arouses students' strong desire to explore new knowledge and enables students to devote themselves wholeheartedly to Exploring new knowledge. )

Let’s talk about the second level, independent exploration and learning new knowledge.

First arrange for students to briefly understand the scale and find the 0 mark, so as to prepare for the next learning of units such as centimeters. Then there is the understanding of centimeters. I plan to let students first focus on establishing the specific concept of 1 centimeter, and then learn how many centimeters they have. On the basis of knowing centimeters, they will learn simple measurements. Specifically, I did this:

1. Understand centimeters. First, let students know that the length between 0 and 1 is 1 centimeter, and then look for where else on the ruler is 1 centimeter? Let students try to summarize what length is 1 centimeter on the ruler, and then establish and strengthen the specific concept of 1 centimeter by closing their eyes and thinking, cutting 1 centimeter of rope, comparing it with thumbtacks, and finding 1 centimeter on themselves. I think examples that are closely connected to life will definitely impress students.

2. Know a few centimeters. Give full play to the role of the ruler in the students' hands and let them count how many centimeters each is from 0 to 5, 4 to 7, 2 centimeters and 4 centimeters from where to where, and how many centimeters there are on the ruler. Focusing on understanding a few centimeters can lay the foundation for the following learning of decimeters.

(From knowing 1 centimeter to knowing how many centimeters, it follows the students’ cognitive rules.)

3. Learn to measure in centimeters. In the design of this link, I will fully reflect the students' autonomy. First, let the students measure the length of the paper strip, and then communicate and explain how the operation is performed. Let the students express their own opinions before summarizing the measurement method. In the method of student communication, it may happen that the scale does not start from 0, or the ruler does not have 0 scale. Here we further allow students to discuss and exchange measurement methods with their deskmates. Finally, let students find objects on learning tools or the body for practice.

(For the method of measuring with a ruler, in traditional teaching, students must measure the object and align it with the 0 scale before operating, but in reality there will be another situation. Therefore, for any The measurement method at the beginning of the scale must not be denied. Measurement is the first time students come into contact with it. We do not directly tell students how to measure. Instead, we let students try it first and then give feedback based on their existing experience and differences among students. To master the method of measurement through mutual communication.)

In the third aspect of exploring new knowledge, I will change my previous practice of teaching decimeters first. Students are often very interested in measuring after they have learned how to measure. However, during the measurement process, they find that the length measured is not a whole centimeter, making it difficult to express accurately, and a new cognitive conflict arises. This is used as a breakthrough to stimulate students' learning. New length unit "mm" of interest.

First count the small grids on the ruler and draw out 1 millimeter. 1 centimeter = 10 millimeters. Then ask what things around you have a length of 1 millimeter. Cut off 1 millimeter with scissors and mark it with a 1-cent coin. Let’s talk about 1 millimeter, and talk about the length and thickness of things that can be measured in millimeters, etc.

(Here I provide students with a large number of perceptual materials prepared before class, because the concept of "millimeters" is more difficult for low-level students to establish than "centimeters". In teaching, through gestures and finding physical objects and observe the thickness of the 1-cent coin provided by the teacher to break through this teaching difficulty. Students will definitely learn happily during the active participation)

Next, ask students to use 1 meter, 1 centimeter, Use a 1 mm rope to measure the length of the edge of the desk, see if there is any difficulty, and introduce decimeter teaching. During teaching, students are directly allowed to cut a 10 cm long rope, intuitively feel the specific concept of 1 decimeter, find the length of 1 decimeter on the ruler, draw the actual length of 1 decimeter with their hands, and find the actual length of 1 decimeter. real thing.

Although this is a weakened link in the entire lesson, teaching decimeters will be easier because students have mastered the learning methods of centimeters and millimeters.

Finally, use ropes of 1 meter, 1 decimeter, and 1 centimeter to compare and measure. You can also discuss and calculate at the same table to figure out the relationship between the three. Letting students do math by hand is better than empty lectures and rote memorization.

(The entire process of exploring new knowledge highlights students’ autonomy in learning. Discover problems, apply knowledge, and solve problems in continuous practical operations. Through learning tools, students are provided with greater thinking space and guidance Students connect operations with thinking, let operations become the source of students' problem discovery, and enable students to "rediscover" new knowledge through operations)

Let's talk about the third level, summarize the whole lesson, and review. tidy. What did the students gain from asking? A simple question can sort out the knowledge of the entire course.

Finally, let’s talk about the fourth level, comprehensive application, deepening and consolidation. Three comprehensive exercises are arranged here. 1. Finger game: The teacher tells the length and the students use their hands to indicate. 2. Help Xiaohong fill in the appropriate unit. 3. Xiao Ming’s diary. (Correction questions) Especially for the last two exercises, I changed the boring style of the past and put the unit filling and correction questions into specific story situations, that is, in life. Because there are many mathematical problems in life, what I have gained will be The knowledge is immediately tested and used to solve problems. This is also the most fundamental purpose of learning knowledge, so that students feel that their learning is useful. Finally, an extracurricular exercise was arranged, and I worked with my parents to make a questionnaire so that I could know the amount of common sense around me. The knowledge in the class was extended and applied, and the relationship with parents was enhanced.

In short, throughout the teaching of the class, I pay attention to the process and methods of how students master and acquire knowledge, as well as the development of problem-solving abilities, cultivate their enthusiasm for loving and using mathematics, and while imparting knowledge, they also Pay attention to the moral life of students. Strive to reflect that students are the real masters of learning! ;