Introduction: Hectares and square kilometers are taught on the basis that students have mastered the common area units of square meters, square decimeters and square centimeters. The teaching difficulty lies in understanding the actual size of 1 hectare. ? Hectares? And then what? Square kilometers? These two land units are relatively large, so it is really difficult for fifth-grade students to form an appearance. The scenes presented in the textbook are unfamiliar to students and lack of perception.

Sharing the teaching experience of hectares and square kilometers, the content of this lesson was originally taught in the fourth and fifth grades in the old textbook. Due to the cancellation of municipal units, the land area is greatly simplified, and only the progress between square meters, hectares and square kilometers is relatively regular, so teaching is carried out in advance. This lesson is based on students mastering some methods to calculate the area of rectangle and square and the conversion between them. In teaching, according to the requirements of new ideas in the new curriculum standards, teachers strive to improve their teaching quality. Teaching? With students? Study? These two aspects have changed greatly. Through hands-on operation, teacher-student cooperation, student cooperation, innovation and other inquiry activities, students can get the calendar of inquiry learning, so as to understand the actual size of 1 hectare and 1 square kilometer and improve their ability to solve mathematical problems in life.

First, feel the mathematical knowledge in the problem situation.

Cultivating students' problem consciousness is an important link in primary school teaching and an important means to activate students' thinking activities. In teaching, teachers create problem situations in time according to textbooks and students' knowledge background, base mathematics learning on students' subjective wishes, stimulate students' active participation, and explore the actual size of 1 hectare and 1 square kilometer.

Second, explore and feel mathematical knowledge in activities.

In learning activities, students are willing to experience and practice by themselves. The student may believe what the teacher told him, but he prefers to believe what he saw and experienced with his own eyes. This is a kind of? Experience? . In teaching, we should pay attention to optimizing the classroom teaching process and methods, so that students can stand on the playground to have a look, evaluate, measure, surround and think, and really feel and experience the actual size of 1 hectare and 1 square kilometer.

Third, encourage students to think independently, guide students to explore independently, cooperate and communicate, and let students become the masters of learning.

In cooperative learning, teachers always? Supporting role? , play a guiding role, students are the protagonists and the main body of learning. Through mutual inspiration and mutual evaluation among teachers, students and groups, we can get real conclusions and complete the construction of knowledge. In teaching, teachers should always pay attention to respecting students, move around more, go off the platform to have activities and discussions with students, encourage students to express their opinions boldly, and strive to create a democratic, equal and harmonious classroom atmosphere.

Sharing the teaching experience of hectares and square kilometers in the teaching process, students find that. The main problem is that the understanding of 1 hectare is not deep enough, which is mainly reflected in filling in the blanks and encountering? The area of the Forbidden City is about 40 ()? At that time, students unconsciously filled in square kilometers, and there were successes and failures in the teaching process, which are summarized as follows.

First,? Big? And then what? Bigger?

The definitions of "big" and "big" are vague. For students, they are familiar with classrooms, basketball courts and large playgrounds, which students have a deep understanding of and can see every day. Based on these, we can realize that 1 hectare is about 208 classrooms, 24 basketball courts and 5 large playgrounds respectively.

Compared with 1 square meter, hectare is a larger unit to measure land area. At this time, it is necessary to give the child a holistic concept, which is related to? Square meters? Yes, so it is 1 hectare = 10000 square meters. Because of its particularity, the enrollment rate is 10000, which also meets the psychological needs of students.

Big is relative, big is relative, because it is relative, so students' cognitive structure will be confused, which will naturally be reflected in not knowing whether to fill hectares or square kilometers. Therefore, to solve this problem, we must establish a standard for students.

In life, it is difficult to find this standard, especially? Square kilometers? Do you think the standards should be based on administrative divisions? City? On this basis, after giving students this standard, it is better to let students feel when to use square kilometers and when to use hectares.

In a word, on the whole, big? In hectares? Bigger? By using square kilometers, this strategy meets students' cognitive needs and helps students rebuild their cognitive structure.

Second,? Experience? And then what? Acquisition?

Thinking with your head, seeing with your eyes and doing with your hands are the general procedures for students to learn mathematics. The process itself is impeccable, but a medium is needed between students, that is, teachers, to play a guiding role. Under the guidance of teachers, students carry out valuable thinking and meaningful exploration activities to acquire new knowledge and form skills.

It is difficult to think about 1 hectare. What is the student's description? Big? 、? Big? This description is based on the surface level. At this time, students have not established the intuitive concept of 1 hectare. In their minds, there is only an area of a square with a variable length of 100 meters, but there is no exact concept.

As mentioned above, three kinds of experience activities are used to help students establish concepts and give practical expansion. The teaching difficulty of 1 km2 is experience. Students can't analogize 1 00 hectare from the concept of1hectare, but in real life, even adults are unfamiliar with the concept of square kilometers.

I thought of a way of thinking in mathematics, called? Incomplete induction? In other words, when we teach square kilometers, the process of knowledge formation takes time, and the process of acquisition is actually a process of experience, debate and speculation.