Paper Keywords: new thinking of mathematics strategy in primary school mathematics calculation
Abstract: Calculation teaching is the teaching of basic mathematics skills in primary school mathematics education. Aiming at some problems in computing teaching under the background of new curriculum standards, this paper focuses on new thinking of teaching strategies from three aspects: the creation of mathematical problem situations, the mastery of basic knowledge and oral arithmetic training, and the exploration and exchange of algorithms.
The Mathematics Curriculum Standard for Compulsory Education clearly points out that it is necessary to "choose the basic knowledge and skills necessary for lifelong learning". Computational teaching, as a basic mathematical skill teaching that runs through primary school mathematics education, is the foundation of mathematics teaching. At present, the calculation teaching under the background of the new curriculum standard not only moderately reduces the calculation difficulty, but also further considers the psychological characteristics of junior students, such as strong curiosity, changeable imagination themes and strong development, and emphasizes the diversification of situation setting and algorithms. However, in actual teaching, too much emphasis on the diversification of calculation methods, far-fetched situational settings and improper grasp of the "degree" of interactive teaching have made teachers fail to play a leading role well and slowed down the development of students' calculation ability. So how to make computing teaching solid and flexible to improve students' computing ability? According to many years of teaching practice experience, the author thinks that we can start from the following three aspects:
First, properly grasp the creation of mathematical problem situations and introduce calculation teaching.
Mathematical problem situation is a real task environment that directly or indirectly points to a specific mathematical problem, including knowledge background, mathematical problem and its representation, operation space and other basic elements. According to the characteristics of mathematics discipline and the age psychological characteristics of primary school students, we can try the following methods to create mathematical problem situations in calculation teaching:
(1) Life experience introduction method. Mathematics is "common sense mathematics". For students, school mathematics learning is only the summary and sublimation of their corresponding mathematics knowledge and experience in their lives. Teachers should pay attention to guiding students to start from their own real mathematical world, form the interaction between teaching materials and life experience, and construct mathematical knowledge. For example, the "preliminary understanding of corners" can arrange for students to discover the meaning of each corner in geometric figures from red scarves, books and other physical objects; "Understanding of Yuan, Jiao and Fen" can start with daily activities such as buying snacks.
(2) Real problem simulation. It is mainly to establish a direct connection between the representation of real problems and the mathematical problems to be studied, and to construct the problem situation through refined attractive representations. For example, "dividing by remainder-chartering", the situation of chartering can be simulated as the use of hula hoops, which are used to refer to ships. There are 4 people in each hula hoop. 14 people need several hula hoops? In the intuitive demonstration and simulation environment, students can naturally understand the mathematical connotation and basic operation of division with remainder.
Second, lay a solid foundation and strengthen the mastery of basic knowledge and oral arithmetic training.
How to use mathematical concepts, algorithms or formulas is the first consideration in solving calculation problems. Whether we can understand and master these basic knowledge directly affects students' computing ability. For example, in elementary arithmetic, it is necessary to understand the laws of elementary arithmetic, such as 95-5× (1-0.5). Students should understand the basic knowledge of multiplication and division before doing addition and subtraction, and first understand the operation of calculating brackets, so as to ensure that the calculation is not wrong. Compared with junior students, senior students have more basic knowledge, so computing teaching should pay more attention not to rush for success, and start with the basic knowledge already learned and carry out transfer training. When teaching fractional addition with different denominators, we should start with the meaning of addition and fractional unit. Guide students to think: can different units of scores be added directly? Then guide students to use general knowledge, turn differences into similarities, and turn problems into the addition of fractions with the same denominator.
The same is true of verbal arithmetic training. As the basis of computing ability, oral calculation is a mathematical skill that relies only on thinking calculation and quickly obtains the calculation results. Oral arithmetic is widely used in daily life and study, which plays a direct role in cultivating students' memory, attention and thinking ability. Therefore, in the cultivation of students' oral arithmetic ability in lower grades of primary schools, it is especially necessary to adhere to the teaching principle of "focusing on peacetime and perseverance". For example, the addition and subtraction within 20 and the multiplication table of 1999 should all be blurted out. For the long-term familiarity and consolidation of students' oral calculation methods, teachers should promptly promote students' proficiency in calculation methods to transform into basic mathematical skills and enhance the effectiveness of calculation teaching.
Third, independent exploration should go through the process of algorithm exploration under the guidance of teachers.
Understanding the abstract logic of mathematical knowledge is the central link of learning activities and computing teaching. In teaching, teachers should pay special attention to make students complete psychological activities from concrete to abstract in behavior, representation and symbolic operation, and deeply understand arithmetic.
(1) The old and new knowledge are closely related, which stimulates the formation of positive transfer. Students' thinking is effectively led to the connection point of old and new knowledge, but students can master new knowledge points faster and enter a new level of mathematical understanding. For example, for the carry addition operation of adding two digits, the teacher can pass 17+ 18=? 12+9=? Examples like this guide students to compare the algorithmic relationship between the addition of two digits and the addition of two digits to one digit, that is, the addition and subtraction of numbers on the same digit, full of ten into one. When students master the relationship between old and new knowledge, teachers should also guide students to understand the essence and avoid negative transfer by comparing and analyzing the relationship between them under the premise of controlling the classroom. As simple as a large number, 700+500=900, and students can get 7+5= 12 according to their existing knowledge and experience. At this time, teachers should emphasize the mathematical connotation of the "Seven Represents"-700. These problems seem naive to senior three students, but they can't be ignored in the cultivation of basic mathematics skills.
(2) Algorithm communication. The key to ensure the effectiveness of algorithm communication is to let students learn to listen, question, experience, compare and evaluate. In specific teaching, teachers should grasp the "degree" of dialogue in interactive teaching and the feedback information contained in it to avoid crowding out class hours. We can consider starting with the following words:
For example, "What do you think?" When teachers encourage students to show personalized algorithms, they should also adjust the teaching progress and the teaching design of important and difficult points according to the thinking level of students' algorithms. "Do you have any summary of the calculation rules you have learned now?" Teachers should allow students to make mistakes in generalization, draw correct calculation rules through the supplement and induction of teachers and students, and make students understand more deeply through consolidation exercises. For example, 1000-234, the teacher can sum up the general rule after the students enthusiastically answer: when the abdication subtraction band is 0, the abdication point at 0 becomes 9, and other digital points are reduced accordingly 1. The focus is on students' general mastery of the law of the algorithm.
To create mathematics that conforms to the development of primary school students, the improvement of calculation skills can never be relaxed. Teachers should actively use modern educational technology and teaching AIDS, pay attention to consolidating the learning foundation of mathematics, and integrate the relationship between mathematics and life, so as to really improve the efficiency and effect of computing teaching in lower grades.
References:
This is Zhao Xia. On the cultivation of primary school students' computing ability [J]. New curriculum reform and practice, 20 10( 1 1).
[2] Hao Yu. Cause analysis and countermeasures of simple calculation errors in primary school mathematics [J]. Primary school age: Educational Research, 20 10(05).
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