If a class is introduced properly, it can directly attract students' attention, thus generating good learning motivation, greatly mobilizing students' learning enthusiasm, making the classroom atmosphere relaxed and lively, making classroom activities go smoothly and improving classroom efficiency.
Keywords: mathematics; Import; way
A good beginning is half the battle. A good class is a very important part. It can arouse students' enthusiasm for learning, stimulate their interest in learning, make them think positively and actively seek solutions to problems. Therefore, in classroom teaching, we must attach importance to the art of teaching lead-in. Here are seven ways. In actual teaching, we can choose the appropriate lead-in method according to the teaching content and students' situation.
First, the old knowledge introduction method
Putting forward new questions on the basis of reviewing old knowledge is a method often used in our teaching to introduce new lessons. This way not only conforms to students' cognitive rules, but also paves the way for students to learn new knowledge. Teachers should pay attention to some connections between old and new knowledge in the introduction class, and guide students to think, associate and analyze when asking questions about old knowledge, so that students can feel that new knowledge is the extension and expansion of old knowledge. This will not only enable students to review and consolidate old knowledge, but also eliminate students' fear and strangeness of new knowledge, grasp the connection between old and new knowledge in time and accurately, and achieve the new effect of reviewing old knowledge. For example, in teaching, we can review the triangle mean value theorem with the help of multimedia to arouse students' thinking and lay a theoretical foundation for the proof of trapezoidal mean value theorem. By thinking about the nature of the triangle mean value, we can make analogy connection and introduce the trapezoidal mean value theorem. Then prove the theorem, and the difficulty will be easy to break through. However, in this method of introducing new courses, teachers must carefully select the review content according to the content of teaching materials and students' reality, so that old knowledge can open the way for new knowledge and realize the transfer of knowledge.
Second, the question introduction method
According to the psychological characteristics of middle school students, the method of setting doubts is a method to create some questions, create contradictions, set suspense, arouse thinking, make students have a strong interest in urgent learning, and induce students to change from doubt to thinking and from thinking to understanding. For example, a classmate's wardrobe is inlaid with two identical triangular glasses, one of which is broken. Can you help him draw a piece of the same glass to make it up? The students must be talking about it. Then, the teacher told the students that triangle judgment is needed to solve this problem. Now we use congruent triangles's judgment to solve this problem.
Asking questions is only the first step of questioning introduction, and more importantly, it is to stimulate students' thinking and make students' thinking active as soon as possible. Therefore, teachers must master some questioning methods and skills, and be good at guiding students to learn to think and solve problems.
Third, the story introduction method
Story introduction is one of teachers' favorite methods. At the beginning of class, use stories or allusions to turn students' curiosity into learning interest and promote students' thinking imagination. For example, when we talk about Pythagorean theorem and square root, we can introduce this lesson through the following story:1On a weekend evening in 876, a middle-aged man was walking in the suburbs of Washington State, DC, enjoying the beautiful scenery at dusk. He was then Congressman Garfield of Ohio, USA. Walking, he suddenly found two children talking about something with rapt attention on a small stone stool nearby. Sometimes they quarrel loudly, and sometimes they talk quietly. Out of curiosity, Garfield went to the two children to find out what they were doing, but he saw a little boy bend down and draw a right triangle on the ground with branches. So Garfield asked them what they were doing. I saw the little boy say without looking up, excuse me, sir, if the two right angles of a right triangle are 3 and 4 respectively, what is the length of the hypotenuse? Garfield replied, it's 5. The little boy asked again, if the two right angles are 5 and 7 respectively, what is the length of the hypotenuse of this right triangle? Garfield replied without thinking: the square of the hypotenuse must be equal to the square of 5 plus the square of 7. The little boy added, Sir, can you tell the truth? Garfield was speechless, unable to explain, and his mind was very unhappy, which aroused students' interest in Pythagorean theorem.
Fourth, analogy introduction method
Analogy lead-in is a method to introduce new lessons by comparing the * * * same attributes of two kinds of mathematical objects. If known mathematical objects are familiar and new mathematical objects are compared with known mathematical objects, it is more natural to introduce them. For example, when teaching the nature of similar triangles, congruent triangles's nature is similar to that of similar triangles. The corresponding angles and sides of congruent triangles are equal. The corresponding angles of similar triangles are equal, and the corresponding sides are proportional. If the corresponding sides of similar triangles are equal, then these two triangles become congruent triangles. So congruent triangles is a special case of similar triangles.
Five, direct introduction method
Direct import is the most basic and common import method. At the beginning of the class, the teacher directly reveals the topic, presents the relevant content directly to the students, directly expounds the requirements for the students' purpose in a few sentences, tells or asks questions concisely and clearly, arouses the students' intentional attention, makes them know fairly well and induces their interest in exploring new knowledge. Guide students to distract attention from classroom teaching. Teachers are required to be concise, concise, vivid, clear and enlightening, so that students can have a sense of need and urgency and stimulate their learning motivation. For example, the introduction of algebra addition and subtraction: we have learned the related concepts of algebra, the rule of merging similar items, and the rule of removing brackets and adding brackets. In this lesson, we will use concepts and rules to learn the addition and subtraction of algebraic expressions.
Sixth, demonstrate the import method.
The process of human cognition is a spiral process of practice and cognition. Suhomlinski said: Students should be allowed to prove one explanation or overthrow another through practice, which means that teachers naturally and skillfully introduce new teaching methods through demonstration experiments of teaching AIDS such as objects, models, charts, projections, movies, computers and courseware. This method can concretize abstract mathematics content, which is conducive to cultivating students to gradually transition from image thinking to abstract thinking. Enhance students' perceptual knowledge, cultivate students' abstract ability from special to general, at the same time, it is also beneficial to cultivate students' rigorous thinking and ability to express problems in mathematical language, help students re-understand the orientation of mathematics discipline and improve their learning initiative. For example, a teacher came into the classroom with a fan in the cold winter, and the students were surprised. On a hot day, teachers never bring electric fans into the classroom. Why did they bring fans to class today? This aroused students' curiosity, and then the teacher turned on the fan and hung it upside down on the blackboard, pointed out the content of today's lecture and found the area of the fan. This introduction is simple, but very innovative.
Seven, operation introduction method
According to the psychological characteristics of junior high school students' strong curiosity and love to move, let students fully use their hands and brains in teaching and actively explore mathematical knowledge, which can not only arouse students' interest, but also enable them to concentrate on developing their thinking, developing their intelligence and actively and happily acquiring knowledge and skills while perceiving things themselves. The introduction of operation can attract students' attention at once, and the atmosphere is warm and relaxed. Make students' learning mood enter the best state from the beginning. For example, when talking about the nature of isosceles triangle, arrange students to make a simple level before class (think about it in the book), and ask students first in class. Please use your level to measure whether your desk is level. How to measure? Why can it be measured horizontally? After learning this piece of knowledge, you can get a solution. It can be seen that hands-on operation is the source of stimulating students' innovative thinking, which can help students consolidate their mathematics knowledge and promote a virtuous circle of teaching. Therefore, students should be properly organized to carry out hands-on operations and experiments in the classroom, explore new knowledge through hands-on brains, actively discover the mystery of new knowledge, and stimulate students' interest in exploration.
In short, there are many ways to import. In mathematics teaching, there is no fixed model for the design of new lesson introduction because of different specific teaching contents and different classes. As long as we are good at studying the characteristics of teaching materials, grasp the key points, attract students with scenery, attract students with emotional and intellectual charm, and fully mobilize students' enthusiasm and initiative, lead-in can become an important link to cultivate students' interest and improve classroom teaching efficiency.