First, the creation of teaching situations in several forms
1. Introduce interests and ideas, create situations and introduce new lessons.
Creating problem situations that make students have contradictions and conflicts in their understanding can stimulate students' psychological state of seeking knowledge and produce urgent learning needs. At the beginning of class, it can attract students' attention and interest, encourage students to think actively, and achieve twice the result with half the effort.
In the case 1, when explaining the new lesson of power of rational numbers, we can take the story of Indian king rewarding chess inventor as the material, set the problem situation to introduce a new lesson, so as to discover the law, try to "how many grains of wheat should be put in the fifth and sixth squares by analogy", and then list the formula for calculating the number of grains in the sixty-fourth square. In this way, the introduction of new courses has increased interest and satisfied students' curiosity. The effect was immediate, and the students immediately paid attention. So that students can feel the need to learn new knowledge in observation, thinking, trying and sorting, and then form a stable interest in learning and a strong desire for knowledge. According to the rules of wheat placement in questions and stories, it can arouse association, make students' thinking active quickly, and make all their psychological activities participate in the study of this class.
2. Ask questions to guide doubts and create situations to explore new knowledge.
Teachers should be good at asking enlightening questions that meet students' cognitive level, creating question inquiry situations, and strive to provide students with space for independent development and opportunities for personal experience, so that students' cognitive level, emotional attitude and values can be improved and they can be harmonious and unified in mathematics learning.
Case 2 In order to let students consolidate the positional relationship between two tangent circles, cultivate students' awareness of question inquiry, and infiltrate the mathematical thought of classified discussion, I arranged such a question situation in the review class.
It is known that ⊙A and ⊙ B are circumscribed with radii of 1cm and 3cm respectively, and ⊙C with radius of 5cm is tangent to ⊙A and ⊙ B. How many can you draw such ⊙C-* *?
Before this, the students have learned the positional relationship between two circles, and have already had two positional relationships of two tangent circles (pictured)-inscribed and circumscribed. On this basis, it is obvious that the conditions for students to actively explore ⊙C (graphic imagination) numbers have been met.
As soon as the question was raised, I found that students with poor foundation were also actively participating and drawing hard. When they got two or three C's, their faces were filled with joy after success. And those top students have the happiness they have experienced. When they introduced the fifth and sixth painting methods of ⊙C, their faces were full of pride and confidence.
3. Connecting with reality, creating life problem situations
Creating problem situations with practical problems can make students feel immersive. Closely link mathematics with students' original life experience, let students feel that "there is mathematics everywhere in life", learn to think about problems with mathematics, and cultivate students' ability to analyze and solve problems with mathematical knowledge.
Case 3 In "One Yuan Linear Equation and Practical Problems", I created the following situations: Smile Hall and department stores in two shopping centers in Guilin held promotional activities to welcome May Day, in which all the goods in Smile Hall were sold at a 60% discount; The department store is an activity of buying two hundred and getting one hundred free. Where can I shop at the same price?
As soon as this question comes out, many students feel closely related to themselves, so they will take the initiative to think and solve the problem. It can be seen that a good situation can enable students to learn useful mathematics inadvertently, thus effectively stimulating students' interest in learning, mobilizing students to actively think and seek knowledge, and constantly trying to explore and solve new problems.
4. People-oriented, creating evaluation education situation
The new curriculum standard highlights the people-oriented education and teaching concept and pays more attention to people's development. Therefore, in the usual teaching, teachers should actively create an evaluation education situation by judging students' behavior, attitude and progress in learning mathematics, so that students can correctly understand themselves, enhance their self-confidence in learning mathematics and gain a real sense of accomplishment.
Case 4 is known; The univariate quadratic equation k2x2+2(k- 1)x+ 1=0 of x has real roots. Find the range of k.
For this problem, students often make such a mistake: because the equation has real roots, () ≥0, so k≤0.5. For such an answer, the teacher is ready to comment: you have left out the condition of k≠0, which does not conform to the definition of a quadratic equation. However, this evaluation obviously lacks encouragement and inspiration, so it is changed to the following evaluation: you have got half the answer and your thinking is very clear. Think again, when k≤0.5, is k=0 ok? Why? The change of this evaluation not only adds encouragement, but also points out the deficiency of the answer and hints at the direction of thinking. Obviously, it can stimulate students' enthusiasm and confidence in learning more than the original evaluation.
5. Make the finishing point and create a classroom summary situation.
In mathematics classroom teaching, new lesson introduction, new lesson explanation and classroom exercise are important, but classroom summary can not be ignored. If the class summary is just right, it can be icing on the cake and make the whole teaching process more perfect.
Case 5 "The diameter is perpendicular to the chord" In the first class, there are only two sentences in the class summary. That is, "in this lesson, we learned a theorem (vertical diameter theorem) and found a method (using the diameter perpendicular to the chord as an auxiliary line to solve the problem about the chord)." This summary is thought-provoking. It only takes a few words to summarize the knowledge learned in this lesson, which plays the role of finishing touch and is convenient for students to master mathematical thinking methods.
In addition, teachers can flexibly create teaching situations according to the teaching content: for example, using information technology to create intuitive teaching situations; Create knowledge transfer situation through analogy and association; Using information technology to create autonomous learning situation; By creating cooperative communication situations through games or competitions, students can independently observe, compare, actively associate, induce and compare, so as to enhance their emotional experience, guide students to learn independently, constantly feel, discover, communicate and evaluate, build their own knowledge, and truly become the main body of learning.
Second, the creation of teaching situations should pay attention to the problems
(1) The situation created should be oriented to all students, and the cognitive level of most students should be considered, which is in line with students' psychological characteristics and cognitive laws.
(2) The created situation should trigger students' cognitive conflicts, stimulate students' interest in learning, promote students' emotional development, and form a correct scientific attitude and world outlook.
③ Situational creation should reflect the characteristics of the subject, closely follow the teaching objectives and contents, highlight the key points of learning, and let students realize the application value of mathematics.
④ Situational creation should focus on connecting with students' real life, be good at discovering, excavating and utilizing students' original knowledge and experience, and make students realize that mathematics comes from life.
⑤ The content of creating situations should be scientific, the difficulty should be moderate and the timing should be appropriate; It should be targeted and purposeful, so that students can think clearly; We should consider diversity and pursue the high efficiency of the situation.
In a word, in mathematics classroom teaching, it is the key to improve classroom efficiency to closely connect with students' reality and create vivid and interesting teaching situations according to their life experience and existing knowledge. It is beneficial for students to learn to observe things and think about problems, stimulate students' interest and desire in learning, and is also an effective way to cultivate students' innovative ability.