First, cultivate students' interest in computing.
Interest is the best teacher. In calculation teaching, we should first stimulate students' interest in calculation, make them willing to learn and do, teach students to use oral calculation, written calculation and calculation tools to calculate, master certain calculation methods, and achieve the purpose of accurate and fast calculation.
Pay attention to the training form and stimulate the interest in calculation. In order to improve students' interest in calculation and make teaching entertaining, students can practice some oral calculations in combination with daily teaching content. While emphasizing calculation, pay attention to the diversification of training forms. Such as: training through games and competitions. Look and listen with cards and small blackboards; Time-limited oral calculation, self-compiled calculation problems, etc. Various forms of training not only improve students' interest in computing, but also cultivate students' good computing habits.
Use typical examples of Chinese and foreign mathematicians or short stories related to classroom teaching content to stimulate interest. In teaching, citing typical examples of mathematicians at home and abroad in time, or adding classroom atmosphere with short stories that students like to hear, can arouse students' interest and interest in mathematics learning, make students concentrate on calculation and improve classroom learning effect.
Second, cultivate a strong will.
Cultivating students' strong will will will promote students to calculate accurately and quickly for a long time.
Keep practicing every day. In computing teaching, oral calculation is the basis of written calculation, and some oral calculation training can be carried out timely and appropriately according to the daily teaching content. In our class, oral arithmetic training of 20 questions every day has become a habit of students. Through long-term persistent training, not only students' strong will is cultivated, but also their computing ability is improved.
In view of the weakness that pupils only like to do simple calculation problems, but don't like to do or do slightly complicated calculations and simple calculations, we should be good at finding pupils' thinking obstacles and overcoming psychological factors that affect students' correct calculations in teaching. We can practice through various methods, such as "solving interesting problems", "clever calculation contest" and encouraging students to solve more than one problem to cultivate students' will.
Third, cultivate students' good computing habits.
Good computing habits directly affect the formation and improvement of students' computing ability. Therefore, teachers should strictly ask students to listen carefully, think carefully, finish their homework independently, review before practicing, study hard in practice, and don't ask others easily or rush to find out the numbers. We should also develop the habit of consciously checking, checking and correcting mistakes.
Teachers should also strengthen the guidance of writing format. Standardized writing format can express students' calculation ideas, methods and steps, and prevent mistakes in writing numbers and operational symbols. Teachers should also set an example for their students. For example, in problem-solving teaching, the examination of questions comes first and the analysis comes last. Clear thinking and distinct levels; The blackboard writing is concise and focused.
When cultivating students' good computing habits, teachers should be patient, unify methods and requirements, persevere and grasp it to the end.
Computing teaching is a long and complicated teaching process, and improving students' computing ability will not happen overnight. Only the joint efforts of teachers and students can achieve results.
Computing teaching in the new curriculum reform should not only introduce specific situations and understand the significance of various operations, but also let students master computing skills and solve practical problems in life. In the arrangement of teaching materials, calculation and application have been merged. In many places, there are no application chapters in old teaching materials, and operations are all sequence and summary chapters. In the arrangement of textbook exercises, there are too few basic questions, many of which are application questions and expansion questions, which leads to the decline of students' basic computing ability. How to give consideration to both to ensure the formation of students' computing skills and the improvement of problem-solving ability? Last semester's summary: "Conclusion 1 Mastering the meaning of addition, subtraction, multiplication and division and teaching calculation can improve the accuracy of calculation and the ability to solve practical problems. Conclusion 2: Strengthening the basic oral calculation training can improve the accuracy and speed of students' calculation. There are oral calculations, estimates and written calculations this semester. On the premise of adhering to the views of last semester, according to the teaching content of computing this semester, the following views are summarized:
Conclusion 1: it is very important to strengthen the basic training of oral calculation, so that students can speak clearly and calculate simply.
When teaching multiplication and division in written form, we should master new calculation skills on the basis of strengthening basic oral arithmetic training, such as 238÷6 19× 19, and all calculations should be based on the original addition and subtraction within 20 and the multiplication and division method in the table. And also summed up the following experience, 1, the teacher finished, don't be too busy to let all the students do it alone, first name a few people to perform and demonstrate on stage, and it will be better to practice after other students judge. 2. Talk less and let students practice more. 3. Explain that writing multiplication and division is a programmed labor, which needs to be linked one by one.
When teaching oral arithmetic, must oral arithmetic be described in written mathematical language? Students usually know how to calculate. I will also use my own words: for example, 600÷3 does not look at the two zeros at the end of 600 first, but counts 6÷3 first, so 600÷3=200. 240÷3 thinks that 3× () = 24,24 ÷ 3 = 8,240 ÷ 3 = 80. Judging from these answers, students can already calculate, but they can't use written terms; I spent a lot of time training students to say: six hundred divided by three equals two hundred, so six hundred and three equals two hundred, and twenty-four tens divided by three equals eight tens, so two hundred and forty and three equals eighty. Judging from the effect, students still work hard to speak.
How to deal with this situation? I thought for a long time and came up with a method of disassembly. When calculating, I will follow the instructions of the students. For example, if 600÷3 is calculated as 6÷3 first, then 600÷3=200. Explain again, without looking at the tail 1 zero, you will see how many tens this number is, without looking at the last two zeros, you will see how many hundreds this number is. You can't watch less for no reason. Through this kind of explanation, the calculation and speaking are separated, so that students can speak clearly and calculate simply.
Conclusion 2: Computing teaching should attach importance to using existing knowledge to promote knowledge transfer, and also attach importance to solving problems through related life experience.
Simple decimal addition and subtraction is based on the previous knowledge of integers and their addition and subtraction. In teaching, I first practiced two pen calculations of 3-digit addition and subtraction. Q: What should I pay attention to when calculating? Then ask students to calculate decimals and summarize the calculation methods. It is concluded that decimal points are aligned and digits are aligned when calculating decimals. Because of contrast and migration, the learning effect is good.
For example, multiplication teaching, 35 rows of 29 students, each row of 700 students. Are there enough seats? Solve practical problems and start importing, explaining the importance of estimation in life. By comparing the three calculation methods, the best estimation method is found, which is convenient for calculation and close to accuracy. Because of the introduction of solving practical problems, students have a certain sense of accomplishment and better motivation to master calculation methods.
In the teaching of writing multiplication, it is also introduced from real life situations, such as how many intersections are there on the chessboard? 19× 19. At first, I asked which students knew how many intersections there were in Go, which aroused great interest of the students. Then, through the calculation of 19× 19, the calculation method and theory are discussed and the calculation results are obtained. Because the calculation result is the answer that students especially want to confirm, the mastery of the calculation process and method is in turn more profound.
In multiplication teaching, paying attention to solving practical problems will enable students to understand the meaning of multiplication more deeply and master the calculation process and method more firmly.
For example, in the unit of teaching problem solving, a calculation problem is also highlighted. Do the application problems solved in two steps have to be listed as comprehensive formulas? "Must students master the ability to combine into comprehensive formulas?" The key to solving problems in teaching should be to analyze practical problems and determine what to seek first and then what to seek. Because the textbook arrangement is combined into a comprehensive formula in Example 1, I also spent some time talking about how to combine two related step-by-step formulas into a comprehensive formula in Example 1 teaching:
5×50=250 people
250×6= 1500 (person)
The merging method is to replace 250 in the second formula with 5×50 in the first formula. In the exercise of Example 2, I also pay attention to cultivating students' ability in this respect and realize the benefits of enumerating comprehensive formulas. However, with the increase of comprehensive formulas, some children don't know when to use brackets and when not to use them. What's first? What is confusion? Need to review the operation order of the comprehensive formula. However, this aspect is not arranged in the teaching materials and syllabus. However, through the investigation of previous mathematics textbooks in this volume, there is no separate arrangement for this content. Due to class problems, should I teach or not? Is it worthwhile to spend too much time on this calculation problem when teaching application problems? "Do we have to master the ability to combine into comprehensive formulas?" Through discussion, we also made correct treatment, added a class hour, and summarized and reviewed the operation order of the comprehensive formula.
Conclusion 3: It is very valuable to cultivate students' estimation ability and give them a good sense of numbers. (This paragraph is written in sections.)
The national compulsory education mathematics curriculum standard (experimental draft) (hereinafter referred to as the standard) pointed out in the second issue of Teaching Suggestions: "Estimation is widely used in daily life and mathematics learning, which is of great value to cultivate students' estimation consciousness, develop students' estimation ability and make students have a good sense of numbers." A large number of estimation teaching and open teaching concepts in the new textbooks make me feel confused and stressed. How to cultivate students' estimation consciousness and develop students' estimation ability is a problem I think and study in teaching. I will talk about my understanding and practice on my own estimation teaching for several years.
First, pay full attention to the cultivation of estimation consciousness, so that students can gradually form a good sense of numbers.
The Standard points out in the Teaching Suggestion of the first issue of Curriculum Implementation Suggestion: "Estimation is widely used in daily life. In low-level teaching, teachers should seize the opportunity to cultivate students' estimation consciousness and preliminary estimation skills. "In fact, estimation, as a kind of ability and consciousness, must be infiltrated by teachers in their usual teaching. In the usual teaching, we should use the teaching situation, life examples and students' own life experience and intuition to estimate, strengthen the cognition of data, and gradually make students have a good sense of numbers.
Before teaching the concept of number in the lower grades, I will ask students to estimate the number of objects presented first, and then count them, so that students can gradually establish the concept of number and enhance their estimation ability. After teaching "length unit", you can design some examples with estimated values for students to practice. For example, a skipping rope is about (), a playground is about (), and a pen is 15 ().
Students' good data consciousness and quantitative ability are not only manifested in the extraction and processing of data, but also in "being able to estimate the result of operation and explain the rationality of the result". For example, 125÷2 378÷5. What do you think the estimate should be? Of course, many students regard 125 as 120 and 375 as 350,350 ÷ 5 = 70, which is in line with the estimation strategy of "rounding up the whole number, and the smaller the difference from the exact result, the better", but many students still regard 125 as/kloc-. So I organized children to debate, let them freely exchange their own estimation methods, compare their own estimation results, give their own reasonable explanations for the estimation results, and then the teacher evaluated them in time, which greatly enhanced the students' estimation ability invisibly.
Secondly, according to the needs of teaching situation, the estimation strategy should be used flexibly and reasonably.
In the second issue of the Standard, it is emphasized: "In the process of solving specific problems, we can choose appropriate estimation methods and develop the habit of estimation." In the actual teaching, there is a case: the teaching situation is shirt 68 yuan, shorts 34 yuan, and mother brings 100 yuan. Are these two enough? Most students still use the "rounding" method: 68+34 ≈ 100. The answer is enough. Only a few students put forward different opinions. I asked these students to talk about their own ideas. A classmate said: I estimated it and calculated it accurately, and found that it was not enough to buy these two things at 102 yuan. Another classmate said: People can't buy things without more money, so I estimate that 68 is 70 and 34 is 40, which adds up to 1 10 yuan, so it's not enough to bring 100 yuan. From this case, it can be seen that the estimation should be combined with the specific situation, not simply by "rounding off", but by combining the actual life and adopting flexible estimation strategies.
There is another situation: a barrel of mineral water is about 58 cups, and Xiao Ming has to drink at least 5 glasses of water a day. How many days does this bucket of water last for Xiao Ming? The answer is 1 1. According to the conventional estimation method, 58 is closer to 60, which should be 12, which is closer to the exact number and is a suitable answer. But the following topic has an additional condition (Xiaoming should drink at least 5 glasses of water every day), that is, the minimum divisor is 5. Then, according to the requirements of real life, the truncation method in division estimation should be adopted, and the answer is 1 1.
Therefore, in classroom teaching, teachers should seize the opportunity to provide students with estimation situations, reasonably penetrate estimation and adopt flexible estimation methods. Let students consciously use estimation, improve their interest in estimation, form estimation consciousness and flexibly adjust estimation strategies.
Third, give full play to the role of estimation and tap its teaching value.
As a new content of the key reform of the new curriculum standard, estimation naturally has a very wide range of practical value and is widely used in daily life. For example, every family should plan their family's income and expenditure. What is the turnover and profit of this shopping mall? These all need to be estimated. In fact, estimation provides an important basis for judging whether the calculator is accurate, including whether the results of children's oral and written calculations are reasonable. In teaching, teachers should combine the needs of real life, penetrate into drip teaching, let students fully understand the role of estimation, and form the habit of estimating first, calculating later, estimating again and testing again. In practical teaching, I often enter a misunderstanding: I attach great importance to the practice of estimation methods in teaching, but ignore the analysis and explanation of estimation results. In fact, I think it is more important to analyze and explain the estimation results and evaluate the students' estimation methods in teaching than to give them the estimation methods. Students' evaluation strategies are formed through teachers' continuous evaluation and analysis. The new curriculum emphasizes the use of mathematical methods to solve practical problems. In teaching, we should pay attention to the analysis and evaluation of estimation results, and judge the relationship between estimation results and accurate answers in combination with the specific situation of life, that is, the problem of "big estimation" and "small estimation".
In a word, as a math teacher, we should cultivate students' estimation ability, teach estimation methods and use estimation skills flexibly, and give students a free, happy and developed math world.