First, the problems in the teaching of mathematical calculation in primary schools
1. Problems in teachers' teaching
(1) Teachers pay attention to the scene and life of mathematical knowledge, and downplay the essence of mathematics. It is understandable to introduce computing knowledge from life situations, but it is essential to abstract, summarize and summarize the concepts, principles and laws related to computing. Otherwise, it is difficult to form computing ability and training thinking.
(2) Recalculate the principle and ignore the algorithm. Because the textbook downplays the summary of laws in the presentation of calculation content, students often rely on exploration experience and consolidation exercises to improve their mastery of calculation methods. This leads to low learning efficiency and high error rate.
(3) Teachers excessively pursue the "quantity" of algorithm diversification, but ignore the "quality" of the most basic algorithm, blindly guide students to use various methods to calculate as much as possible, and even appear algorithms that violate cognitive laws.
(4) Teachers unilaterally "demand" multiple algorithms in order to mine the preset methods, without highlighting the basic algorithms; The algorithm is diversified, but the teacher does not guide students to analyze and compare various calculation methods and choose the best one, which is not conducive to students to form systematic calculation knowledge.
(5) The way to deal with students' homework and exam mistakes is not personalized and targeted. Teachers often explain in class, and then ask students to copy the wrong questions again. This kind of treatment is relatively extensive, lacking in personalization, and the effect is not good.
2. Problems among students.
The influence of students' psychological factors is carelessness, that is, their perception level is rough, their attention is not concentrated, and their attitude is not correct enough; Influenced by knowledge factors, the concept, nature and law of mathematics are lacking, and the application is not skilled enough; The negative influence of thinking mode.
Second, find strategies to rebuild the value orientation of computing teaching.
1, reasonably locate the teaching objectives, strengthen the teaching of mathematical calculation and solve problems, and show the calculation value.
In addition to paying attention to most intermediate students, the determination and implementation of teaching objectives can also be flexible, pay attention to a few students with learning difficulties and excellent students, give appropriate guidance to students with learning difficulties in class, and focus on completing basic questions to ensure the correct rate. Excellent students should appropriately supplement the expanding resources in the teaching materials and improve their methods and thinking.
Strengthen the grasp of the concept, nature and law of mathematics. Concepts, properties, laws, formulas and quantitative relations in primary school mathematics are the basis for further learning mathematics. Teachers should strengthen the teaching of basic knowledge and systematize and structure mathematical knowledge. Teachers should carefully analyze and study teaching materials, make full use of materials to explain the truth, guide students to grasp its connotation, identify the key points, difficulties and mistakes in teaching, improve teaching quality, and enable students to firmly grasp the rules and make correct calculations. In addition, when teachers find students' mistakes, they must give timely guidance to make up for students' knowledge defects, so that the calculation error rate can be effectively controlled.
In solving problems, the value of computing teaching is highlighted. For computing teaching, the new textbook boldly breaks the traditional arrangement mode of the old textbook, organically integrates computing teaching with problem solving, makes computing teaching rely on problem solving, highlights the significance of computing, enriches computing strategies and cultivates computing literacy. For example, in the teaching of "Four Arithmetic", through the theme map, ask: "What mathematical information did you get from the map? According to the mathematical data, what mathematical problems can you solve? " Then let the students learn mixed operation in solving problems. Teaching calculation in solving problems not only cultivates students' ability to collect information, but also helps students understand why calculation is needed, so as to have a deeper understanding of arithmetic and algorithms. Of course, this can stimulate students' interest and make them realize the close relationship between mathematics and life more than single calculation teaching.
2. Feel the harmony between arithmetic and algorithm.
Arithmetic is the bridge for students to move towards algorithm, and it is the basis for students to learn algorithm, and algorithm is the central task for students to learn. If we only emphasize arithmetic, we can solve the problem, but we can't achieve a qualitative leap in calculation methods; On the contrary, if we only emphasize the algorithm, it is like building a castle in the air, which is difficult to stabilize. Therefore, it is necessary to realize the harmony and unity of arithmetic and algorithm in teaching.
For example, the teaching fragment of "two digits plus two digits"
(When teaching "36+23", students appear four calculation methods)
(1) swing;
(2) dial the counter;
(3) The combination of verbal calculation, because 30+20=50 6+3=9 50+9=59.
So 36+23 = 59;
(4) The column is vertical.
……
In order to guide students to communicate the relationship between arithmetic and algorithm, teachers ask the following questions:
"How to dial the counter?"
"Dial three tens and six ones first, then two tens and three ones."
"Why do you dial like this?" ……
This leads students to understand that "the same numbers can be added up".
When swinging the stick, the teacher also asks the students to understand why the whole bundle is added to the whole bundle and the single bundle is added to the single bundle, and understand that their mathematical meanings are also added by the same number; When the combination of "30+20=50 6+3=9 50+9=59" is divided by oral calculation, let students understand that the mathematical meaning of this calculation is still the addition of the same digits.
The teacher's task in it is to inspire students to realize that "whether dialing, swinging or counting are based on the addition of the same numbers", which is the key for students to understand the vertical writing form. In fact, the first three methods are pregnant with the rule of column vertical calculation, and all three calculation methods contain the same idea-the numbers on the same number can be added directly, so we should write the formula according to the writing format of the same number alignment. This vertical format is actually a concise expression of the above three or more calculation methods. After understanding this arithmetic, students master the method of vertical calculation.
Therefore, while fully embodying the diversified teaching value of the algorithm, teachers should actively guide students to optimize the algorithm, and turn the optimized algorithm into another opportunity for students to develop their thinking and ability. At the same time, teachers should not only evaluate its correctness, but also evaluate its rationality and scientificity.
3. Promote the integration of diversification and optimization.
The diversification of algorithms can cultivate the flexibility of students' thinking. Advocating algorithm diversification is the highlight of the new curriculum reform, which not only meets students' individualized learning needs, but also carries the mission of "making different people get different development in mathematics", and its advantages are obvious. In classroom teaching, teachers should create enough time and space for students, encourage students to think independently, try boldly, use their brains and find out their own calculation methods.
Like teaching "9+8=?" In the calculation, the students put forward some algorithms through thinking:
Set up learning tools. Put nine first, then eight, one * * *17;
Divide 8 into 1 and 7,9+1=10,10+7 =17;
Divide 9 by 2 and 7, 8+2 = 10,10+7 =17;
Nine minus eight equals17;
8×2= 16, 16+ 1= 17;
……
Students find the most suitable method in the process of trying, which not only cultivates their innovative consciousness and habits, but also improves their computing ability.
4. Strengthen personalized teaching.
After completing the main tasks in classroom teaching, teachers should know the students' learning situation in time by asking questions, practicing and patrolling, and carry out hierarchical teaching and counseling, so that different students can have different development, and at the same time carry out follow-up learning without leaving any problems. The treatment of students' wrong questions is not to let students copy the correct answers, but to analyze the mistakes, find out the reasons and give targeted personalized counseling.
5. Improve students' psychological level.
(1) Strengthen the training of students' perception level. The hearing of junior students is relatively developed, but their eyesight is weak. Teachers should pay attention to the visual training of reading books on blackboards and textbooks, such as reading aloud and copying numbers and formulas from Grade One.
(2) Strengthen the training of students' attention.
In order to train students' attention, we can take the form of comparative exercises, such as 23×4 and 24×3, 3.4 1.5 and 34. 1.5, 75+27 and 75-27.
(3) Strengthen the cultivation of students' good study habits.
Teachers usually ask students to write neatly and regularly, and then calculate them step by step after seeing the figures clearly. Students who are easy to copy mistakes can write while reading, and must check after calculation.
6. Strengthen the training of students' perception level.
The junior students' hearing is relatively developed, but their eyesight is weak. Attention should be paid to the visual training of reading blackboard books and textbooks. For example, we should pay attention to reading training and copying calculation from the first grade.
7. Carry out activities to broaden the horizon of computational learning.
In classroom teaching, teachers should fully consider the characteristics of students' physical and mental development, combine students' life experience and existing knowledge, design interesting and meaningful activities, and improve students' interest in learning mathematics. For example, math competition, quick calculation competition, oral calculation competition, tabloid design and so on; You can also organize mathematical practice activities to guide students to connect with real life applications and guide students to practice in life.
8. Pay attention to the teaching of new types of calculation problems.
With the deepening of the new curriculum reform, on the basis of mastering basic traditional computing skills, students can deepen the thinking content of computing problems and get closer and closer to life. Primary school mathematics can solve many kinds of problems in life and should not be limited to traditional calculation problems.
In a word, computing ability can't be cultivated overnight. As a primary school math teacher, it is not enough to just pursue the excitement and fun of computing teaching. We should think more and try more, and attach great importance to improving the effectiveness of computing teaching, so that students can learn more solidly.