The Curriculum Standard of Primary Mathematics points out that the basic starting point of mathematics teaching is to promote students' all-round, sustained and harmonious development. Students should be fully developed in the limited teaching time. Therefore, in the current curriculum reform, we must pay enough attention to how to improve the "effectiveness" of classroom teaching.
The effectiveness of teaching includes three meanings: effectiveness refers to the evaluation of the consistency between the results of teaching activities and the expected teaching objectives, and teaching effect refers to the teaching quality of each class; Effective, teaching efficiency = effective teaching time/actual teaching time × 100%, which refers to the teaching workload completed in unit time; Benefit refers to the income of teaching activities and the realization of the value of teaching activities.
How to improve the "effectiveness" of classroom teaching? After three years of curriculum reform, I think we should have a scientific, rational and pragmatic understanding of new ideas, new curriculum standards, new textbooks and new teaching methods.
First, how to understand "algorithm diversification", "multiple solutions to one problem" and "algorithm optimization"
The basic idea of modern education is "student-oriented development", which should not only face the whole people, but also respect differences. In mathematics teaching, if teachers want to promote students' all-round development, they should respect students' personality, not make a one-size-fits-all approach, and create mathematics education that promotes the rapid development of each student. Therefore, in view of the disadvantages of single algorithm in previous computing teaching, the new curriculum puts forward "algorithm diversification"
For example, the textbook "abdication and subtraction in 20 years" in the first grade of primary school mathematics experiment textbook published by People's Education Press suggests the method of "breaking ten" and "trying to add and subtract"
You can use "minute" and "continuous decrease". So for the first-year students, it is hard to say which of these algorithms is better and which is worse. Students can use and choose different methods to calculate according to their own experience. Teachers should respect students' independent choice, protect students' enthusiasm for independent discovery, and advocate and encourage the diversification of algorithms.
There is a difference between "multiple solutions to one question" and "algorithm diversification". Generally speaking, "multiple solutions to one question" is aimed at individuals, especially students with above average level. When they encounter the same problem, they can have a variety of ideas and solutions, aiming at developing the flexibility of students' thinking. "Algorithm diversification" is group-oriented, and everyone can use the algorithm they like or know best. At the same time, when the algorithm is diversified, he can learn the advantages of others or change his original algorithm through communication and evaluation. Therefore, students should not be required to say several algorithms for the same problem in teaching to reduce their unnecessary burden.
But mathematics pays attention to "optimization", and the meaning of "algorithm optimization" in mathematics is to find the simplest, easiest and fastest method. This point, teachers should be very clear in classroom teaching, guide students to compare and evaluate responsibly, and let students master those recognized best, optimal and most basic algorithms. I have seen some calculation classes, and there are more than a dozen algorithms to discuss a calculation problem. The teacher kept urging me: Is there any other way? It took up a lot of classroom teaching time, and it was not until the class was over that I said: You can use your favorite method to calculate. As a result, some slow-thinking students in the class were dazzled and confused, and finally they didn't know which method was the best. Is this kind of teaching too inefficient?
Second, how to put the position of "situation setting" and "teaching content" and "teaching effect" right?
In the classroom of the new curriculum, we see that some teachers have spent a lot of effort on "situational setting", which really makes the classroom active and wonderful. However, in some classes, teachers spend too much time and energy on this link, but they deviate from the content of classroom teaching and lose the efficiency of classroom teaching.
What kind of "situational setting" should we advocate in curriculum reform? What is the function of "situational setting"? This is what we must find out. The "situational setting" advocated by the new curriculum has the following functions: first, it provides materials and activities rich in children's interest, arouses students' interest and mobilizes their enthusiasm; Secondly, provide students with familiar problem scenarios or cognitive contradictions, stimulate students' interest and enthusiasm for inquiry, and realize that mathematics comes from life and is used in life; Thirdly, the situation is not just an introduction, but the cognitive basis of related learning activities.
Mathematics is abstract, but for children, they often use their own life experience to "interpret" mathematical phenomena. For example, People's Education Publishing House, the second volume of mathematics in the third grade of primary school, "Preliminary Understanding of Decimals", is the first time that students come into contact with decimals. In order to reduce the difficulty of understanding decimal abstraction, the textbook creates a familiar situation for children: the price of goods in the store. In the situation, let students use the existing knowledge about Jiao Yuanfen to understand the meaning of decimals and the addition and subtraction of decimals, so that students can learn kindly, interestingly and easily. This situation is the cognitive basis for students to learn decimals, and it is also an effective and efficient teaching method.
Also in the "Elementary Understanding of Decimals" class, a teacher created such a situation: we came to the kingdom of numbers, and the numbers 1, 2,3 kicked the ball. A moment 1 runs ahead: 1.23, a moment 2 runs ahead: 2. 13, ... nearly 65433. A lot of teaching time is wasted, but students still don't understand the meaning of decimals. Does this situation reduce the efficiency of classroom teaching?
Third, how to treat learning methods such as "hands-on practice", "independent exploration" and "cooperative learning"
The curriculum standard points out: "Students' mathematics learning activities should be a lively, positive and personalized process." "Hands-on practice, independent exploration, cooperation and communication are important ways for students to learn mathematics. "The textbook" Primary School Mathematics Experiment "published by People's Education Publishing House attaches great importance to the cultivation of learning methods, and pays attention to creating more opportunities for students to explore, practice, communicate with their classmates and share their exploration results while students are listening and practicing in class, so as to better understand the basic knowledge of mathematics, form basic skills and master mathematical methods.
"Hands-on practice" and "cooperative learning" can not be satisfied with students' superficial "lively operation and participation", but should pay attention to what students are doing, what practical effects their hands-on practice has produced, whether they have aroused and developed students' mathematical thinking, how teachers can play a guiding role while encouraging students to explore independently, where is the best intervention period for teachers' guidance, and what is the knowledge base and experience support for students' independent exploration.
However, in some classes, learning methods such as "hands-on practice", "independent inquiry" and "cooperative learning" often become a mere formality without content. For example, in the second volume of the second grade, the lesson "Finding Quotient by Multiplication Formula of 2-6", for example, 1, the little monkey broke the peach, and calculated 12÷3=? I asked several students, all of whom were calculated by the average score and multiplication formula. The teacher added: discuss in groups, and score one point with one stick. At this time, students have lost interest in exploring the topics they have already done, and most of them are playing with sticks. This kind of cooperative learning and independent inquiry is a bit too formal. This formalization wastes effective teaching time and loses the value and significance of teaching activities. How to reflect the "effectiveness" of classroom teaching?
Fourth, how to inherit and develop the excellent tradition of mathematics teaching in China?
Education reform and curriculum reform have become the world trend, and education experts all over the world are studying education. However, curriculum reform is a continuous innovation of education, not a left-right movement. Therefore, we should treat the curriculum reform with a normal heart. Curriculum reform is not a total denial of traditional teaching, but an inheritance and development of excellent teaching tradition. For example, "students preview" is a good traditional teaching method. Before previewing, you can give an outline of the questions to guide students to think positively; Or ask: what did you know after previewing? Cultivate students' ability to read, analyze and sort out materials.