How to make the exercises in mathematics classroom exude the breath of the new curriculum, further optimize the exercises, enable students to master knowledge, form skills, and improve their ability to analyze and solve problems is a problem that teachers should think about under the new curriculum concept. According to my own teaching practice and research, I talk about the effectiveness of classroom exercises.
First, the flexible content of classroom exercises can stimulate students' interest in learning.
Interesting exercises can make students interested in learning activities, stabilize students' attention, deepen students' thinking and stimulate students' initiative and enthusiasm in learning. When designing, teachers can tap the internal strength of exercises according to the teaching objectives, design games, guess riddles, walk mathematical mazes, conduct oral exercises, written exercises and practical exercises. Can complement, match, fill in the blanks, draw pictures, etc. Only in this way can we really make every student move and let students "think" and fly. Only by allowing students to participate in learning activities can you have a desire and interest in learning, thus generating a strong learning motivation. At this time, even if students encounter difficulties, they will overcome them and study more actively, so that practice will have a multiplier effect. For example, the lesson of "prime numbers and composite numbers" is an abstract and boring concept teaching. In order to prevent students from being tired of learning, I have carefully designed the following exercises. 1-20, odd numbers have _ _, even numbers have _ _, composite numbers have _ _, and prime numbers have _ _. This exercise is for students to complete independently. Then ask the students to discuss in groups and complete "What did you find?" The students have come to many conclusions, such as: prime numbers are not all odd numbers; Composite numbers are not always even. In this way, not only the types of questions have changed, but also the practice forms reflect the characteristics of combining individuals with groups. In order not to lose interest, I designed a topic to guess the telephone number: (1) a number that is neither prime nor composite; (2) the smallest odd prime number; (3) the approximate number of 6; (4) Minimum multiple of 9; 5] the smallest odd number; [6] the product of the smallest prime number and the smallest composite number; (7) Numbers with only one divisor; The smallest natural number; Levies prime numbers divisible by 25; ⑽ Minimum number divisible by 2 and 3 at the same time; ⑾ The smallest even number. Next, I also designed an activity to introduce my student number with what I have learned. This design unifies knowledge and interest.
Second, design classroom exercises in a targeted and hierarchical way.
First of all, we should accurately grasp the key points and difficulties in the knowledge structure of each part according to the teaching content and the proposed teaching objectives; At the same time, it should conform to the students' thinking characteristics and the objective laws of cognitive development. Secondly, we should follow the development order from easy to difficult, from simple to complex, from basic to variant, from low to advanced, so that students at different levels can have a happy and pleasant successful experience after studying hard and make their learning more active. For example, in the teaching of fractional division with the divider as the decimal, the teaching emphasis is on "seeing" (seeing how many decimal places the divisor is) and "moving" (moving the decimal point of the divisor to make the divisor an integer, and then moving the decimal point position of the divisor accordingly). In view of this, I designed an exercise that only lists the vertical type and does not require calculation first: 0.36 ÷ 0.9; 2.8÷0.07; 2.8÷0. 14; 0. 102÷0.5 1。 After these problems are solved, future exercises will be easy. For another example, when teaching the commutative law and associative law of addition, I designed a set of exercises with strong hierarchy: the first level (basic problem) simply calculates the following problems: 35+240+25, 56+75+44+ 15. The second level (variant question) simply calculates the following questions: (72+33)+(67+28), (143+69)+(57+131). At the third level (comprehensive questions, where new knowledge is properly combined with old knowledge), the following questions can be simply calculated: (96+49)+ 157, (92+58)+(45+ 108), (68+76)+32+24. The calculation of the fourth level (problems developed by those who have spare capacity): 2+3-4+5-6+7-8+9-10+12+13-14. In this way, all students can do what they can, taste the joy of success, have more confidence in mathematics learning and be more active in learning.
Third, design typical and life-oriented classroom exercises.
A class is only 40 minutes, and time is limited. Therefore, the design of our classroom exercises should be few and precise, which requires that the exercises we design should be typical, which can not only reflect the essence of classroom teaching content, but also achieve the purpose of consolidating knowledge, expanding thinking and cultivating basic skills through design exercises. For example, when teaching "Find the area of a combined figure", I designed an exercise: Find the area of the shadow part in the figure. Students make the four shadows move by communicating with the existing knowledge system. Using the change after moving, not only the area of the shadow part is obtained, but also the method of calculating the area of the shadow part when the middle blank part is at any position in the figure is summarized. Designing a problem leads to the solution of multiple problems, which can be described as killing two birds with one stone. For another example, when I was teaching "Understanding RMB", I designed such a life situation exercise: "Going to the supermarket". Divide the class into several groups, and act as customers and salespeople respectively, to see which salespeople can collect and exchange money correctly and quickly, and which customers will plan to spend money and buy what they need most (prepare all kinds of goods and price tags in advance). The content of this lesson is to know the price of goods on the basis of being familiar with the face value of RMB, which is closely related to the life of students and originated from life. Therefore, create such a situation, so that students can consciously apply their existing knowledge to life practice. Moreover, it can consolidate the understanding of RMB and understand the unit conversion of RMB. And kill two birds with one stone.
Fourth, open classroom practice.
Compared with closed exercises, openness generally refers to exercises with incomplete conditions, incomplete questions, unique answers and inconsistent problem-solving methods, which are divergent, exploratory, developmental and innovative. It is conducive to promoting students' positive thinking, activating their thinking, fully mobilizing their internal intellectual activities, and seeking the best problem-solving strategies from different directions. When teaching "Essays with Decimals in Elementary Arithmetic", I designed the exercises in this way: let the students quote four numbers at will, such as 32.8, 4.2, 0.5, 18.75, and let the students compile the essay questions in groups to see which group compiles the most (regardless of exhaustive division). Change the way that teachers set questions and students solve problems in the past, so that students can set questions and solve problems by themselves. It can be said that the conditions, problems and methods are all open, which not only stimulates students' interest in learning, but also optimizes classroom teaching and cultivates students' comprehensive ability to use knowledge. For another example, after learning the surface areas of cuboids and cubes, I asked the students an open question: "How much does it cost to decorate your own house?" See whose decoration looks good and saves money? "Don't think that such a topic is very simple, but it is not. Think about how much knowledge you need: length measurement, surface area calculation of cuboids and cubes, commodity price survey, selection of decoration materials ... This design not only embodies the openness and individuality of mathematics teaching, but also cultivates students' innovative spirit and practical ability, and also helps students master and consolidate their knowledge and skills.
Classroom practice is an important organic part of classroom teaching and an important means for students to master knowledge, form skills, develop intelligence and tap innovative potential. The New Curriculum Standard for Primary Mathematics points out that classroom exercises should not be limited to consolidating knowledge, operating skills and solving standard problems, but should pay attention to informal reasoning problems such as premonition experiments, attempts, induction, conjecture and analogy, open problems with incomplete conditions, unconventional problems with diverse strategies or uncertain conclusions, and unconventional problems with no ready-made steps to follow when solving. This requires teachers to study the textbook carefully, understand the arrangement intention, adjust, combine and supplement the exercises in the textbook appropriately according to the differences of students' knowledge level, organize effective exercises, and be hierarchical, targeted, diverse, open and practical, so as to meet the needs of students of different degrees from both quality and quantity. In a word, effectively improving the quality of mathematics classroom exercises requires the mutual penetration and application of various strategies, and teachers need to adopt corresponding strategies wisely and reasonably under different teaching contents. How to effectively improve the quality of math classroom exercises needs our constant exploration.