First, the reasons for the calculation errors of primary school students
1, poor study habits
Some students have not developed good living habits since childhood and do things carelessly. When they go to study after school, they do not have a good study habit. When calculating, they either read the numbers wrong or wrote them wrong. Either the wrong number is copied or the symbol is omitted; Or forget to carry in addition, forget to abdicate in subtraction, add as subtraction, multiply as division, forget or misplace a decimal point; Sometimes there are even some incomprehensible mistakes.
2. I don't have a good grasp of the concept of calculation rules or operation order.
Some students also despise the study of calculation problems, and often only pay attention to the result (calculation method) and not to the process of the origin of the result. As a result, students can't understand the calculation rules, operation sequence and principle well, but just memorize calculation methods, so students often make more mistakes in calculation. For example, in addition and subtraction, we often forget the borrowed number or the leading number, in division where the last digit of the quotient is zero, and in decimal multiplication, we often forget the decimal point of the product on the point. In elementary arithmetic, we must pay attention to algorithm, intermediate result, operation method, carry and abdication at the same time. Another example is:1.25× (80+4) =1.25× 80+4 =100+4 =104. The reason for the mistake is that I didn't understand 1.25 × (80) when I was studying multiplication and division.
3, the influence of mindset
The negative effect of mindset is mainly manifested in answering completely different questions with customary methods, thus making mistakes. For example: 7.68-2.75+1.25 = 7.68-4 = 2.68 The reason why students make mistakes is that they are easily disturbed by the familiar parts, thus making mistakes. Another example is: 4.9+0.1-4.9+0.1= 5-5 = 0 24× 5 =100 and so on. It is mainly caused by students' wrong mentality.
3, the role of non-intellectual factors
Non-intelligence factors are also an important reason for students' calculation errors. Students are not interested in the importance and correctness of learning. They solve problems only to cope with the teacher's exam, not to be accurate. They are absent-minded and perfunctory, which leads to mistakes. Secondly, there is a lack of patience, and students hope to work out the results soon when calculating. When you are afraid of difficulties, complexity and impatience, you will often make mistakes.
Second, the teaching strategy of cultivating computing ability
The cultivation of computing ability is a systematic project, involving many teaching contents. Students are required to master mathematical concepts and knowledge related to calculation, and transform knowledge into skills and techniques through targeted, multi-level, multi-faceted and multi-form exercises. In order to effectively improve the calculation ability, we must follow the cognitive rules of primary school students and adopt appropriate teaching strategies, so that students' understanding and mastery of mathematical knowledge can develop synchronously with the formation of calculation ability, thus achieving the best teaching effect.
1, master the knowledge about calculation.
(1) calculation rules
Calculation law refers to the general rules that must be followed in calculation, which makes the calculation process procedural and regular and can ensure the accuracy of calculation. Mastering the calculation rules is the guarantee of calculation accuracy.
(2) Operation sequence
Operation order is the stipulation of operation order in the process of elementary arithmetic. Operation at the same level, calculated from left to right in turn; There are two levels of operation, the second level of operation is calculated first, and then the first level of operation is calculated; If there are brackets, you should count them first in the order of brackets-brackets, and then count the ones outside the brackets. Mastering the operation order is the key to elementary arithmetic.
In the teaching of four operations, a teacher encountered a problem. Although he marked the operation sequence first when the students started to contact the four operations according to the tips in the teacher's book, some students still didn't master it well. One day, he wrote two words on the blackboard: "Respect the old and love the young". He said: "Respect the old first, respect the old first. Our relatives include grandparents, parents, siblings. We should give everything to grandparents first, then parents, and finally brothers and sisters. In the big family of operation symbols, parentheses are grandparents. We have to calculate the parentheses first, and multiply and divide the parents. Our second step is to calculate multiplication and division, and finally, brothers and sisters, that is, addition and subtraction. Everyone said, everyone said, operation symbols, who are grandparents, who are parents and who are brothers and sisters? " Next, he asked the children to repeat their corresponding relationships several times by doing a test, and then practice. Later, the situation showed that his method was very useful, and basically no more children made mistakes in the operation sequence.
(3) Operation law and operation nature
Operation law and operation nature are generalizations of objective laws of calculation, which reflect the inevitability of certain changes in calculation under certain conditions. The calculation can be simplified by using the algorithm and operation properties.
2. Find out the reasons and manage according to law.
In the teaching of calculation, some teachers think that calculation is unreasonable. Students can achieve correct and skilled requirements as long as they master the calculation method and practice it repeatedly. As a result, many students can calculate according to the calculation rules, but because of unclear calculation, the scope of knowledge transfer is extremely limited, and they cannot adapt to the ever-changing specific situation in calculation. If we pay attention to the principle of liquidation in teaching, we can make students know both the calculation method and the arithmetic of control method, what it is and why, then the teaching of calculation will certainly become lively and colorful.
(1) demonstrate arithmetic with teaching AIDS.
For example, when the first-year students of mathematics have a preliminary understanding of the nature of "the position and invariance of commutative addend", let them observe the teacher's demonstration first: How many pieces of chalk are there in their left hand and four in their right hand? First left hand, then right hand, the formula is 3+4 = 7, first right hand, then left hand, the formula is 4+3 = 7. Let the students see that the exchange of addends only shows the change of order and does not affect the calculation results. Through demonstration, we can intuitively and vividly explain the position and unchangeable truth of the exchange addend in the addition formula.
(2) Understand arithmetic through the operation of learning tools.
For example, teach carry addition within 20, when the teacher shows 9+2 =? Generally speaking, students can quickly get the sum of 1 1. However, the purpose of teaching 9 plus several is not only to let students calculate the results correctly, but also to reveal the calculation law of carry addition, so that students can master the thinking process of "adding ten" and train their language expression ability. The operation of the learning tools should be carried out step by step under the guidance of the teacher: step one: take out two piles of sticks, a pile of 9 sticks and a pile of 2 sticks; The second part: think about the operation and release the calculation results; The third part: the oral process of operation. Divide 2 into 1 and 1, 9 plus 1 de 1 de1de1de, so as to give students a preliminary understanding of "ten addition". Step 4: Show the thinking process of oral calculation in the formula. Through the teaching of 9 plus several, students have mastered the "plus ten method" initially. When teaching 8 plus a few, 7 plus a few and 6 plus a few, students can apply the "plus ten method" in a wider range to realize the transfer of knowledge.
(3) In combination with the actual situation, talk about liquidation.
For example, when teaching the addition and subtraction of decimals, it is clear that decimal points must be aligned with the help of the relationship between RMB units, angles and the speed of minutes that students are familiar with, that is, two numbers with the same counting unit can be added and subtracted.
(4) Show ideas and define algorithms.
When teaching the calculation rules of four operations, we often use the formulas in dotted lines and boxes to clarify the calculation principle.