As a new people's teacher, classroom teaching is one of our jobs. With the help of teaching reflection, our teaching ability can be improved rapidly. So how to write teaching reflection is appropriate? The following is my reflection on the teaching of mathematical calculation in primary schools for your reference only. Welcome to read.
Reflections on the teaching of mathematics calculation in primary schools 1 One of the important tasks of mathematics teaching in primary schools is to cultivate the ability of calculation. A student who graduated from primary school should be able to calculate the four items of integer, decimal and fraction correctly and quickly, so as to lay a good foundation for further study in middle school. How to realize this teaching requirement?
First of all, we should talk about liquidation principles and laws.
Arithmetic and laws are the basis of calculation. Correct calculation must be based on a thorough understanding of calculation. Students can clearly calculate and remember the rules in their minds. When they do four calculation problems, they can do them in an orderly way.
The mathematical theories that pupils encounter are: the synthesis and decomposition of numbers within 10, the method of adding and breaking ten, the concept of adding the same number, the counting method of decimals, the concept of numbers, the meaning and nature of decimals, the change of decimal size caused by the movement of decimal position, the changing law of product and quotient, the meaning and nature of fractions, the concept of decimal unit, the relationship between fractions and division, and the concept of fractions and general fractions.
Second, make clear the order of elementary arithmetic.
Operation sequence refers to the operation at the same level from left to right in turn. In the formula without brackets, if there is addition, subtraction, multiplication and division, multiply and divide first, then add and subtract; If there are parentheses, use the number of parentheses first, then the number of parentheses.
In primary school mathematics textbooks, this part of knowledge about arithmetic sequence is scattered. There are two-step addition and subtraction problems in grade one, two-step calculation problems (without brackets) in grade two, two-step calculation problems (with brackets) in grade three, and three-step calculation problems in elementary arithmetic order in grade four, which will continue to be consolidated in grades five and six.
When explaining the operation sequence, students will encounter the following problems:
First, students will make the following mistakes in off-line calculation. For example,
36- 135/9 or 36- 135/9
= 15(36- "not copied down) = 15-36 (the positions of the two numbers are reversed)
36- 135÷9=2 1
= 135÷9 (ignoring the significance of solving calculation)
This kind of mistake often appears among students in lower and middle grades. The teacher should explain repeatedly why the order can't be changed and why the uncounted parts should be copied.
Second, if you don't carefully examine the questions, you will make perceptual mistakes or copy the wrong numbers and symbols.
For example, 3.5+ 1.5-3.5+ 1.5 (should be equal to 3, but get 0 by mistake); 236-36×5 (which should be equal to 56 and get 400 by mistake) and 756÷4×25 (which should be equal to 4725 and get 7.56 by mistake) are all caused by incorrect operation sequence.
For such problems, we should strengthen practice in teaching, and we can also carry out comparative exercises to attract students' attention to the operation order. Such as: 75÷25×4, 75 ÷ (25× 4); 240- 15×6+ 10,
240-( 15×6+ 10)。
Third, it is necessary to clarify the significance of the operation law.
Primary school textbooks mainly talk about the commutative law and associative law of addition, and a property of subtraction: "A number MINUS the sum of two numbers is equal to this number MINUS two addends in turn." And the commutative law, associative law and distributive law of multiplication. These laws are applicable to the operation of integers, decimals and fractions at the same time, and are widely used.
When explaining, students should first understand the meaning of these laws. It is difficult for students to master the nature of subtraction and the distribution law of multiplication and division. In teaching, we can cite familiar examples and draw some intuitive charts to illustrate them. On the basis of students' understanding, ask them to remember the meaning of law. They will be asked to express the law in words.
Secondly, students should be able to perform simple operations according to the algorithm. Students should be inspired to perform simple operations according to the numerical characteristics of the problem.
In order to improve students' reasonable and flexible computing ability, it can also guide students to change the operation order and form of some topics and make the calculation simple. For example, 240× 18 ÷ 72 = 240 ÷ (72 ÷18) = 240 ÷ 4 = 60 (according to the divisor, it is 4 times of the multiplier18, and it is directly divided by 4); 560×15 ÷ 8 = 560 ÷ 8×15 = 70×15 =1050 (using the exchange law); 240 ÷ 15× 60 = 240× (60 ÷15) = 240× 4 = 960 (according to the multiplier, it is 4 times the divisor15, and directly multiplied by 4); 18×35= 18×5×7=630 (decompose 35 into 5 and multiply it by 7); 81÷ 36 = 81÷ 9 ÷ 4 = 9 ÷ 4 = 2.25 (divide 36 first, then divide 9 and then divide 4), teaching reflection "Reflections on the Teaching of Mathematical Calculation Course in Primary Schools".
Fourth, strengthen basic knowledge teaching and basic skills training.
Some knowledge should be trained in classroom teaching, so that students can blurt it out accurately. Only in this way can the calculation be correct and fast. For example, addition and subtraction within 20, multiplication formula and so on.
In elementary arithmetic, an important part of strengthening basic training is to strengthen the teaching and practice of oral arithmetic.
Oral calculation is the basis of written calculation. The skill of written calculation is the development of oral calculation, which is based on the rules of written calculation and after several oral calculations. Take 987×786 as an example, it needs 9 multiplications and 14 additions. It can be seen that there are errors in oral calculation and errors in written calculation. Therefore, not only the basic training of oral arithmetic in middle and low grades should be sustained, but also the senior grades should pay equal attention to it with the expansion and deepening of the learning content. This will not only help students to consolidate concepts and rules in time, increase the density of classroom teaching and improve their computing ability, but also cultivate students' thinking agility, attention and memory by guiding them to think actively and use knowledge flexibly in oral arithmetic training.
① Pay attention to the calculation method. Multiplying two digits by one digit 23×2, two twenties are 40, two threes are 6, and 40 plus 6 makes 46, which is the thinking process of multiplying two digits by one digit. In teaching, students should master the steps of oral calculation to prevent blind practice.
② Various forms of exercises. Look at the calculation, listen and let the students tell the results directly. Lower grades can also play math games, find friends, send letters, win red flags or engage in math competitions to stimulate students' interest in learning.
For the key and difficult knowledge in teaching materials, we should pay more attention to strengthening basic skills training. For example, there is a division of 0 in the middle or at the end of the quotient, which makes it easy for students to lose 0. In order to prevent such problems, you can arrange the following exercises:
Let's talk about the following questions first, and then calculate.
43344÷869844÷494343÷43 1 1600÷58
Because students judge how many digits the quotient is before doing the problem, such as 9844÷49, and the quotient should be three digits. If the quotient 1 is not enough in the calculation process, students will realize that quotient 0 occupies a position.
5. Organize exercises in a planned way.
In order to improve students' computing ability, we should also attach importance to the teaching of arithmetic and rules, the teaching of elementary arithmetic progression and the teaching of arithmetic rules, and organize exercises in a planned way.
Basic oral calculation and basic calculation should be practiced every day, and individual calculation should be focused according to the students' mastery, highlighting the points that students are difficult to master and easy to make mistakes. When arranging exercises, the topics can be carried out in the order of consolidating basic knowledge, improving basic operation skills and forming operation skills.
First, train students to read the questions in the form of written narrative questions. 240- 15×6+ 10 is pronounced as: what is the sum of 240 minus 15 times 6 plus 10?
Second, train students to talk about the operation sequence. For example, 0.46+(36-765÷25)×25.
This problem includes addition, subtraction, multiplication, division and brackets. You have to calculate the division in parentheses first, then the subtraction, then multiply the result in parentheses by 25, and finally the subtraction. At the beginning of learning, students can also indicate the operation order in the formula.
Third, contrast exercises.
Put the confusing and error-prone questions together, let students distinguish and compare, and improve their ability to distinguish.
For example, point out the different operation orders of the following groups of questions, and then calculate.
① 120× 10÷5 120×( 10÷5)
②80+60÷ 1280+60- 12
Fourth, fill in the blanks.
In order to break through the difficulties, the key places in the textbook can be practiced in the form of filling in the blanks.
① Fast algorithm of addition and subtraction.
348+ 198=348□200□2
5 14-396=5 14□400□4
638-599=638-□+□
728-69-3 1=728-(□○□)
② Multiplicative distribution law 201× 42 = (□□□□□ )× 42 = □× 42+□× 42.
98×65=(□○□)×65=□×65○□×65
76×28+76×72=□×(□○□)
39×42+42=(□○□)×□
Fifth, correct mistakes.
Write down the typical and representative error board in the exercise, and let the students point out the mistakes and explain the reasons. And correct it. For example, 80×5÷80×5= 1 54-54÷6=0.
Sixth, interesting exercises.
In order to stimulate students' interest, we can also do some interesting exercises appropriately.
Improving students' computing ability is a meticulous and long-term teaching work. In addition to the above work, we should also pay attention to the guidance of students. In class, problems in students' calculation can be found and solved in time through students' answering questions, oral calculation, blackboard writing performance or written homework, so that students' mistakes can be eliminated in the bud. It is also very important for teachers to carefully correct homework, analyze the causes of errors, find out the rules of errors, and pay attention to cultivating students' good habits of examining, doing and searching questions.
Reflections on the teaching of mathematical calculation in primary schools 2 "Derivation of the formula for calculating the volume of a cylinder" is based on students' knowledge of the calculation of the area of a circle, the volume of a cuboid and the understanding of a cylinder. At the same time, it is also a lesson to prepare students for further learning other physics knowledge in the future.
At the beginning of the class, teachers create problem situations, guide students to use existing life experience and old knowledge to explore and solve practical problems from time to time, create cognitive conflicts, and form a "task-driven" inquiry atmosphere.
In the first part, the teacher provides a platform for students to operate, observe and discuss, so that students can accumulate geometric knowledge from time to time in the process of experiencing and exploring space and graphics, thus helping students to understand the actual three-dimensional world and gradually develop the concept of space.
Exercises layout pays attention to the close connection with real life, so that students can solve two problems in the introduction by using a formula for calculating the volume of a cylinder that they have just deduced, so that they can understand the value of mathematics and actually experience that mathematics exists around them. Mathematics is very useful for understanding the world around us and solving practical problems.
Teachers properly guide students to transfer knowledge in the introduction and new lessons, so that students can fully feel and experience "transformation", an important thinking method to solve mathematical problems. At the same time, the rational use of multimedia technology vividly shows that "the more sectors are divided, the closer the three-dimensional figure is to the cuboid", which organically permeates the original idea of limit.
Reflections on the teaching of three courses of mathematical calculation in primary schools. Junior high school teachers often complain that students' computing ability is poor and primary schools have not laid a good foundation. As a primary school math teacher, I feel very guilty. An important task of mathematics teaching in primary schools is to cultivate the ability of calculation. A primary school graduate should be able to calculate integer, decimal and fraction correctly and quickly, laying a good foundation for further study in middle school. In order to achieve these goals, I think computing ability can be cultivated in this way, combined with my usual teaching:
First, talk about the principles and laws of liquidation, and strengthen the teaching of basic knowledge and the training of basic skills.
Arithmetic and laws are the basis of calculation. Correct calculation must be based on a thorough understanding of calculation. Students can clearly calculate and remember the rules in their minds. When they do four calculation problems, they can do them in an orderly way. The teaching situation shows that students' computing ability is directly proportional to their oral expression ability. Oral calculation is the basis of written calculation, and the skill of written calculation is the development of oral calculation, which is calculated through several oral calculations according to the rules of written calculation. Take 987×786 as an example, it needs 9 multiplications and 14 additions. It can be seen that there are errors in oral calculation and errors in written calculation. Therefore, not only the basic training of oral arithmetic in middle and low grades should be sustained, but also the senior grades should pay equal attention to it with the expansion and deepening of the learning content. This will not only help students to consolidate concepts and rules in time, increase the density of classroom teaching and improve their computing ability, but also cultivate students' thinking agility, attention and memory by guiding them to think actively and use knowledge flexibly in oral arithmetic training.
Second, attach importance to estimation and check the correctness of calculation through estimation.
The syllabus clearly puts forward that students should have estimation consciousness and preliminary estimation ability. "Estimation" has penetrated into the whole set of teaching materials and should be applied to the whole calculation teaching in teaching. For example, there is a division of 0 between teachers, 428÷4, and many students will write the answer as 12. When this kind of error occurs, teachers should not only explain the theory and calculation process clearly, but also combine the estimation, so that they can form the habit of checking the calculation results through estimation, which can effectively improve the accuracy of calculation.
Third, we should study students' psychology.
The students' calculation accuracy is not high. The reason is that only a few students have not mastered the calculation rules and methods, and most students classify it as "carelessness", but this is actually only a superficial phenomenon. The main sticking point is that students' bad psychological quality in computing leads to their bad computing habits. When students calculate, because they are divorced from the analysis and examination of problems, they only regard calculation as simple addition, subtraction, multiplication and division subconsciously, and they have a lazy psychology in their hearts, thus lacking the psychological quality of internal control. In this state of mind, students will not have the psychology of "simple questions are often easy to make mistakes", "I want to calculate carefully" and "I want to do everything right". Its external performance is that when calculating, look around and do what you say, it is difficult to concentrate on calculation, put it aside when you are finished, and do not develop the habit of testing, taking finishing first as the standard, not doing it right. There are still some students, especially those in the lower grades, who have not developed the habit of careful inspection and look around when they are finished. In order to solve these problems, teachers should help students analyze the reasons for doing wrong together, so that every student can realize that "carelessness is just an excuse, and insufficient attention is the most important thing."
Fourth, practice in various forms to improve the interest in calculation.
When arranging exercises, questions can take the following forms:
First, train students to read the questions in the form of written narrative questions. 240- 15×6+ 10 is pronounced as: what is the sum of 240 minus 15 times 6 plus 10?
Second, train students to say the operation order, such as: 0.46+(36-765 ÷ 25) × 25;
Third, contrast exercises. Put the confusing and error-prone topics together, let students distinguish and compare, and improve their recognition ability;
Fourth, fill in the blanks. For example, the fast algorithm of addition and subtraction is 348+198 = 348 □ 200 □ 2;
Fifth, correct mistakes. Write down the typical and representative error board in the exercise, and let the students point out the mistakes and explain the reasons. And correct it. For example, 80× 5 ÷ 80× 5 =154-54 ÷ 6 = 0;
Sixth, interesting exercises. In order to stimulate students' interest, we can also do some interesting exercises appropriately.
In short, computing power is not cultivated overnight, but a long-term and continuous process. Therefore, our teachers at all stages should attach importance to the cultivation of students' computing ability. After the initial formation of computing power, it must be consolidated, developed and deepened in future applications in order to gradually improve.
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