Evaluation draft of the second volume of the fourth grade mathematics of Shanghai Education Publishing House: Addition and subtraction of decimals.

# Teaching Plan # Introduction Decimal addition and subtraction is taught on the basis that students master the meaning and nature of integer addition and subtraction and decimal. Its meaning is the same as integer addition and subtraction, and the calculation rules are the same as integers in arithmetic, all of which are numbers added and subtracted on the same digit. I have not prepared the following contents for your reference!

Tisch

First of all, scientific and reasonable teaching objectives are helpful to computer teaching. Teacher Li has a good grasp of the starting point of students' learning, and on this basis, she has formulated the teaching objectives. Decimal addition and subtraction is a part of calculation problems, so it has the general characteristics of calculation problems, which is easy for students to master, but boring. If you just talk and practice blindly, students' interest will be lost and their study will be very passive. And Mr. Wang's scene creation is relatively successful. At the beginning of class, students' desire for learning was stimulated. Let students actively explore and seek knowledge in happiness. Shopping activities in supermarkets make students really feel that mathematics is around them and have a strong interest in mathematics, thus stimulating students' requirements for learning mathematics. Let students truly appreciate the value of mathematics, so as to be closer to mathematics. And really realized the true meaning that mathematics comes from life and is applied to life. Then use students' favorite tricks and card-drawing games to constantly enliven the classroom atmosphere. Stimulating interest in learning has become the characteristic of this class.

Secondly, in terms of knowledge and skills, Mr. Li created a realistic supermarket shopping scene, allowing students to actively explore the calculation method of decimal addition and subtraction. Through orderly teaching activities, students can correctly calculate and solve related practical problems. This kind of teaching is based on the transfer of old knowledge. The creation of this situation conforms to students' real life, from "mathematics in life" to "mathematics in textbooks", which mobilizes students' initiative in learning and can really serve the exploration of new knowledge. In addition, after teaching decimal addition and subtraction, the teacher guides students to use what they have learned to solve some practical problems in life. Faced with the key and difficult point of "why should decimal points be vertically aligned", the teacher organized students to have group discussions and cooperative exchanges. Starting from the understanding and expression of personality, the calculation method of "decimal addition and subtraction" is independently refined. Digital alignment is decimal point alignment, which allows students to find the calculation method of decimal addition and subtraction in doing and speaking. It is discovered independently on the basis of students' full experience and feelings, and it becomes the result of students' "re-creation" of knowledge. It is beneficial to cultivate students' creative thinking, help students learn and use mathematics in happy middle schools, and thus cultivate students' language expression ability.

Thirdly, in terms of emotional attitude, Mr. Li has carried out a series of mathematics activities, allowing students to master new knowledge through independent exploration, cooperation and exchange, and play games on the basis of understanding mathematics and mastering algorithms. Then guide students to think about calculation methods, sum up their gains and consolidate new knowledge.

extreme

The focus of this lesson is the calculation method of decimal addition and subtraction, and the difficulty is the arithmetic of decimal addition and subtraction. Teacher Cao asked the students to study together (* * * to discuss the calculation method of decimal addition and subtraction) and expand their study (give the podium to the students and let them talk about the calculation process).

What if the percentile exceeds ten? How to deal with the shortage of ten places? The decimal places are different. What should I do when calculating? Can the zero at the end of the number be removed? They can solve all these problems. In other words, in this process, students understand arithmetic and master the algorithm. In this way, students can experience it personally, not only grasp the key points of knowledge, break through the difficulties, but also improve their oral expression ability. Lay a foundation for future practice and students' lifelong development.

So I think Mr. Cao has achieved a better goal in this class. Highlight key points and break through difficult points. This is a good lesson worth learning.

Tisso

1, explaining the arithmetic of decimal addition and subtraction. For example: 53.40-49.80, it is not easy for students to talk about arithmetic, but through group cooperation and class discussion, some students tell the reasons for their mistakes, and some students naturally say that the same numbers are not aligned or the numbers in the same counting unit can be added or subtracted.

2. Pay attention to students' learning, strengthen students' autonomous learning and promote the implementation of three-dimensional goals. The whole class takes the learning process as the center, pays attention to digging and using the mistakes made by students in practice, pays attention to facing the whole class, listens to the students' speeches wholeheartedly, gives them the opportunity to correct their mistakes and successfully shows themselves. By analyzing mistakes and establishing correct values, all students can experience the value of mathematics in their study.

3. Pay attention to the development of students' independence, cultivate students' autonomous learning ability and sense of learning responsibility, strengthen the pertinence of teaching, and let students have real cognition, gain and mathematical perception in this class.

4. Teachers' lessons are dug deeply and thoroughly, and efforts are made to expand students' exploration space.

Teacher Shi's class makes people see the content of thinking in class and expands the thinking space of students. Her class is not only to let students know why, but also to let students explore why and guide students to explore the knowledge behind the law. Students' thinking is always deepened step by step in the teacher's doubts. Students have gone through the thinking process of tracing the source, which is the process of scientific inquiry, that is, learning science independently and constructing knowledge. Teacher Li's in-depth excavation of the classroom also lies in well-designed questions, which have space and conform to the thinking characteristics of students. Therefore, such problems promote the development and exercise of students' thinking.

5. Harmonious teacher-student relationship.

Classroom belongs to students, so students should be given time to study, think and discover. Mathematics is not to learn much knowledge, but to really train and inspire students' thinking. In this class, Miss Li hardly talks about it. All she did was ask questions at key points, make appropriate summaries, and guide students to deepen their thinking step by step. Students are always in the main position of inquiry, so they have really been exercised. The teacher seldom talks.