(1) Attach importance to students' life experience and closely link mathematics with reality.
(B) Show the process of knowledge generation and application, and form the basic narrative mode of "problem situation-modeling-explanation and application"
(3) Take mathematics activities as clues to promote students' independent participation, exploration and communication.
(D) Pay attention to students' emotional experience and create a relaxed and harmonious learning atmosphere.
(e) From the shallow to the deep, step by step and spiral upward.
(6) Highlight the interconnection and integration of knowledge.
(7) Pay attention to the mathematics learning needs of different students.
(eight) combined with appropriate materials to reflect the cultural value of mathematics.
Second, the basic content of teaching materials and the characteristics of various fields
(a) the field of numbers and algebra
(b) Space and graphics
(iii) Statistics and probability
Practical and comprehensive application fields
Through hard work, on the basis of the first and second editions of experimental textbooks, the author completed the compilation of six textbooks for primary school mathematics in the new century, and passed the examination and approval of the national primary and secondary school textbook examination and approval Committee. More than 2.4 million first-year students in China have tried this textbook. However, there are still many unsatisfactory places in the textbook. We are soberly aware that the construction of teaching materials is endless, and the curriculum reform needs constant exploration. It is not only an encouragement and affirmation, but also a responsibility and expectation to use the textbooks compiled by the standard group in the experimental area. Therefore, we sincerely hope that teachers can feedback the problems and suggestions for revision to us in time while using this textbook, so that we can continuously improve the quality of the textbook.
For the development of every student and the rejuvenation of the Chinese nation. We are duty-bound to provide the next generation with the best quality mathematics education!
First, the guiding ideology and basic characteristics of textbook compilation
This set of teaching materials follows the educational idea of "education should face modernization, the world and the future", and draws lessons from a large number of successful experiences of foreign curriculum and teaching materials reform on the basis of learning the experience of previous primary school mathematics curriculum and teaching materials reform since the founding of the People's Republic of China. At the same time, textbook writers fully consider the universality, foundation and developmental characteristics of compulsory education in China, and also fully consider the mathematical requirements of citizens in the future society, and strive to form the following basic characteristics of textbook compilation.
(1) Attach importance to students' life experience and closely link mathematics with reality.
Paying attention to students' life experience and letting students learn new knowledge from existing knowledge and experience has become the basic understanding of the current international mathematics curriculum reform. Every child at school has rich life experience and knowledge accumulation, including a lot of experience in mathematics activities and strategies for solving problems by using mathematics; At the same time, in real life, students can be widely exposed to the rich mathematical world such as number, quantity, space, graphics, data, possibility and relationship. Therefore, the textbook attaches great importance to the connection between mathematics and reality, on the one hand, it pays attention to the connection with daily life and real space; On the other hand, it pays attention to the connection with students' reality, that is, students' existing experience, knowledge, ability, emotion, attitude and interest. Based on students' life experience, the textbook designs many interesting and mathematically valuable situations in students' life, so that students can learn, understand and apply mathematics in the process of studying problems. For example, in the study of number and operation, the textbook highlights the practical meaning of logarithm and the understanding of operation meaning, and emphasizes that students should discuss realistic or interesting problems and apply what they have learned in the process of solving problems. In the study of space and graphics, the textbook broadens students' horizons to the space of human life. Through the study of three-dimensional graphics and plane graphics introduced by objects around students, the contents closely related to students' life experience such as location determination and graphic transformation are added. In the study of statistics, the textbook arranges a large number of topics around students, encouraging students to make judgments by collecting data, sorting out data and analyzing data. At the same time, the textbook also arranges learning contents that students like, are willing to accept and think about, such as "math games", "math stories" and "inquiry activities". The purpose of arranging these colorful contents in the teaching materials is to let students learn, understand and apply mathematics from the examples around them or the problems they are interested in.
With the growth of students' age and the expansion of activity space, teaching materials gradually lead students' vision from their own world and surrounding environment to a wider space such as real society, science and technology, choose richer materials, and pay special attention to digging up issues rich in the flavor of the times. For example, in the study of understanding numbers, the textbook highlights the close relationship between numbers and real life, and arranges rich materials such as "Fighting SARS", "Rapid Development of Education in China", "Western Development", "Marine Resources in China", "Nine Planets in the Solar System", "Three Gorges Hydropower Station", "Rocket Speed" and "Building Area of National Library" for students to learn from the environment, society, science and so on.
(B) Show the process of knowledge generation and application, and form the basic narrative mode of "problem situation-modeling-explanation and application"
The textbook arranges important mathematical contents according to the narrative mode of "problem situation-modeling-explanation and application", that is, creating a familiar problem situation, gradually establishing a mathematical model of this problem through observation, practice, exploration, thinking and communication, and then using this model to explain some phenomena or solve some problems. Through the above process, students will gradually master basic mathematical knowledge and methods, form good mathematical thinking habits and application consciousness, improve their ability to solve problems, feel the fun of mathematical creation, enhance their confidence in learning mathematics well, and gain a more comprehensive experience and understanding of mathematics.
For example, in the second volume of the third grade, the textbook begins with learning. The textbook creates a situation of sharing apples, and encourages students to get "an apple for two people on average and half an apple for each" according to their life experience. Traditional textbooks often introduce meaning, reading method and writing method here, which not only ignores students' life experience and creative potential, but also fails to show the superiority of learning mathematical symbols. In fact, the noun "semi" appeared in students' spoken English before their formal academic achievements, but they just didn't want to use any symbols to express it. Based on this, the textbook allows students to discuss how to express "half". In the discussion, on the one hand, students can realize that the number they have learned is not enough, and they should find another way to express "half"; On the other hand, students are encouraged to use their imagination and boldly create ways to express "half". On this basis, "half can be expressed in words" is introduced, and through the comparison of various expressions, the superiority of expressing "half" in words is realized, and the necessity of learning scores and the superiority of mathematical symbols are felt. In fact, this is to let students experience the process from problem situation to modeling. Furthermore, in the process of operation and description, such as "daubing", "folding" and "talking", the textbook makes students understand that not only half an apple can be represented, but also half a leaf, half a piece of clothes, half a piece of paper and so on, which further explains and applies this model and makes students feel the role of the mathematical model. Of course, in this process, students understand the specific meaning of music score, know the names of various parts of music score, and initially master the writing and reading of music score.
Practice has proved that this basic narrative mode of teaching materials is helpful for students to learn, understand and apply mathematics in the process of studying specific problems from life experience and objective facts. This mode has also broken the "injection" teaching mode taught by teachers in the past, and provided students with a lot of opportunities for observation, operation, experiment, thinking and communication. At the same time, this model not only helps students to master the connotation of mathematical knowledge, but also helps to guide students to learn mathematical thinking, improve their ability to solve problems and develop a good emotional experience.
(3) Take mathematics activities as clues to promote students' independent participation, exploration and communication.
Since the 1960s, China's primary school mathematics textbooks have basically been presented in the form of "examples and exercises", and this form has basically been preserved in many subsequent textbook adaptations. Textbooks often introduce what they have learned through simple examples, and then arrange some examples. When students understand the examples, the corresponding supporting exercises will be arranged in the teaching materials to give students the opportunity to practice. The main purpose of this is to have a typical topic for teachers and students to refer to in teaching activities, so that students can master and evaluate teachers easily. It is clearly pointed out in the standard: "Mathematics teaching activities must be based on students' cognitive development level and existing knowledge and experience. Teachers should stimulate students' enthusiasm for learning and provide them with opportunities to fully engage in mathematics activities. Help them truly understand and master basic mathematical knowledge and skills, mathematical ideas and methods in the process of independent exploration and cooperation and exchange, and gain rich experience in mathematical activities. " Textbooks provide basic clues for students' learning activities. "This actually requires that the presentation of traditional textbooks must be changed.
According to the requirements of "Standard", the textbook broke through the previous presentation mode centered on examples, and began to learn relevant knowledge with students' mathematical activities as clues. The textbook has columns such as "Take a look", "Do it", "Think about it", "Say it", "Read it", "My Growth Footprint" and "Question Bank" to help students master basic knowledge and skills, develop mathematical thinking and problem-solving ability, and initially form good feelings and attitudes in activities such as observation, operation, thinking, communication and reflection.
For example, in the study of "Symmetric Graphics" in the second volume of Grade Three, the textbook embodies the process of "intuitive understanding-experiencing the overall characteristics of symmetry in operation-applying characteristics (distinguishing, drawing and imagining)", and designs various activities such as observation, operation, imagination, thinking and communication. First of all, encourage students to intuitively understand symmetry by observing and appreciating folk paper-cutting; Then, through the operation activities of "stacking, cutting, cutting" and "guessing, cutting and cutting", the overall characteristics of symmetry phenomenon are gradually perceived; Then you can identify whether the figure is symmetrical, draw (enclose) the symmetrical figure on the square paper (nail board), spread the symmetrical figure out, and further experience the characteristics of the symmetrical figure.
It is of great significance to let students experience colorful mathematical activities. First of all, it represents the new requirements for the quality of citizens. In order to adapt to the future society, citizens' practical ability, innovative spirit, cooperative communication ability and lifelong learning ability must be gradually formed in personal practical activities. Second, it represents a comprehensive understanding of mathematics. Mathematics is not only a collection of objective knowledge, but also a creative and socialized mathematical activity under the guidance of rules and practices formed by practice. Thirdly, it represents the repositioning of the teaching process. Learning activity is an active construction process based on students' existing knowledge and experience; Teaching process is a part of mathematics practice and a challenging "re-creation" by teachers and students. Teachers can teach in various ways according to the characteristics of various mathematical activities, so as to promote students' active participation, independent thinking and cooperative communication more effectively, so as to understand what they have learned. Fourth, ensure the full realization of the curriculum objectives. It is not only the goal of mathematical thinking, problem solving, emotion and attitude, but also the students' personal practice and self-experience. The acquisition, understanding and application of knowledge and skills are also inseparable from mathematical activities. Fifth, it provides a broad space for students' personality development. Not only can all students participate in the activities together, but each student can think and explore from different angles according to his own life experience, knowledge accumulation, cognitive level and personality tendency; It not only improves the initiative of students' participation, but also meets the diverse learning needs. Of course, emphasizing the importance of mathematical activities does not exclude the importance of results, and the two complement each other.
(D) Pay attention to students' emotional experience and create a relaxed and harmonious learning atmosphere.
The standard establishes the field of emotional attitude on the basis of knowledge and skills, mathematical thinking and problem solving, and clearly points out that the development of emotional attitude values is neither an educational goal unrelated to mathematics curriculum nor a "by-product" of mathematics knowledge teaching, but an important goal of mathematics education itself. In the process of mathematics teaching, the development of students' emotions, attitudes and values is not naturally formed after learning some specific concepts, laws and formulas, but should run through the whole process of mathematics teaching, and its realization needs to accumulate over time. However, once it is formed, it will benefit students for life. Therefore, the teaching materials pay attention to students' emotional experience from beginning to end, and strive to create a relaxed and harmonious learning atmosphere for students.
Relevant research shows that cognitive participation and emotional participation are closely related in the process of students' participation. The close combination of "knowledge" and "emotion" is one of the basic laws in the teaching process. Specifically, students' deep cognitive participation in mathematics classroom learning activities is closely related to students' positive emotional experience (pleasure and success), especially deep cognitive styles (such as imagination, exploration and innovation) are closely related to pleasure; Shallow cognitive participation (such as memory, imitation and mechanical training) is closely related to students' anxiety and boredom. Therefore, the textbooks create a large number of realistic, interesting and challenging situations, which not only enable students to learn mathematics knowledge in specific situations, but more importantly, stimulate students' thirst for knowledge and make them enjoy engaging in mathematics learning activities.
Specifically, the textbook mainly promotes students' positive emotional experience from two aspects. On the one hand, the diversity and interest of presentation forms are used to stimulate students' interest in learning mathematics. For example, introduce cartoon characters "naughty", "smiling" and "wise old man" that students love to see, design fascinating plots, and stimulate students' curiosity. Students will gain positive emotional experience in the process of learning cartoon characters. But this interest is often superficial and shallow, and will gradually disappear with the growth of students' age. Therefore, on the other hand, teaching materials encourage students to get close to, understand and talk about mathematics by showing the richness and infinite charm of mathematics itself, which is the main way to promote students' curiosity and thirst for knowledge. For example, teaching materials focus on showing the close relationship between mathematics and the real world, and the selection of materials and the design of questions focus on combining students' life experience, so that students can feel the role of mathematics in their own lives and attract them to participate in mathematics learning activities; The textbook focuses on displaying colorful mathematical activities, designing challenging questions and feeling the successful experience of mathematical creation; The textbook focuses on showing the close relationship within mathematics, so that students can feel that mathematics is a whole; Teaching materials focus on showing different problem-solving strategies or different thinking methods, so that students can feel the richness of mathematical thinking and meet the needs of different students; The textbook has designed small columns such as "Math Story", "Math Game" and "Do you know", which not only makes students feel the fun of math learning, but also broadens their learning horizons. In short, only when students truly appreciate the charm of mathematics itself can they actively participate in mathematics learning activities and maintain their positive feelings for mathematics learning for a long time.
(e) From the shallow to the deep, step by step and spiral upward.
The cognitive characteristics of primary school students are from shallow to deep, and the understanding of mathematical knowledge is not completed at one time, which needs to go through a process of gradual deepening and improvement. At the same time, the goals of the first and second phases proposed by the standard are the ultimate goals that students should achieve at the end of the term. Therefore, according to students' knowledge base, psychological development law and knowledge characteristics, the textbook adopts the structure of gradually expanding and deepening the content of four fields. Each grade is not only focused, but also pays attention to consistency.
For example, for the study of decimals, the most direct experience of students' understanding of decimals comes from price. Therefore, when learning decimals for the first time in the first learning period, the textbook has designed units of "yuan, jiao, fen and decimal", which is intended to let students learn in the situation of yuan, jiao and fen (such as "buying stationery", "shopping around", "buying books" and "delivering books"). The study of this unit also provides an intuitive and concrete model for learning decimals in the future. In the second phase of learning decimals and their operations, the textbook first expands students' understanding of decimals through rich examples; When students explore decimal arithmetic, they can use the model of element, angle and minute, and finally master decimal arithmetic without specific model.
(6) Highlight the interconnection and integration of knowledge.
When compiling textbooks, we should pay attention to the vertical connection between the contents of each part, so that the former part can lay a good foundation for the latter part, and the latter part is the development and perfection of the former part. At the same time, the textbook also pays attention to the horizontal connection and synthesis between the contents of each part, and strives to make the knowledge in all fields form a whole. By showing these relationships, students can form a preliminary understanding of mathematics as a whole, use other mathematical concepts to deepen their understanding of a concept, and use various models and methods to explore problems and describe results.
Thinking with numbers (symbols) and shapes are two important ways of thinking. The combination of numbers (symbols) and shapes is an important aspect of the relationship between mathematical contents, and the textbook reveals the relationship between them through the combination of multiple contents. For example, in the course of "Knowing Numbers within 10,000", the textbook has designed the activity of putting small cubes, so that students can have an intuitive experience of numbers. For another example, for the study of "the basic nature of fractions", the textbook designs the activities of origami paper strips. Through continuous origami strips, the activities of the shadow part are represented by scores, so that students can intuitively realize that both the numerator and denominator are multiplied by the same number (except 0), and the size of the score remains unchanged, which also reflects the combination of numbers and shapes.
In order to help students solve problems comprehensively by using the knowledge and methods they have learned, and to further understand the connection and synthesis of knowledge, the textbook has carefully designed practical activities and comprehensive application activities, including problem-solving activities, problem-solving strategy learning, and law-exploring activities.
(7) Pay attention to the mathematics learning needs of different students.
Psychological research shows that every student has the potential to analyze, solve problems and create. The key is to provide good materials in the course content to promote students' development. Of course, because there are some differences among students, their development needs are also different. According to the psychological law of students' mathematics learning, the selection of teaching materials not only ensures the smooth implementation of the basic curriculum objectives proposed in the standard, but also takes into account the needs of meeting different students' mathematics learning needs. Therefore, for the same problem situation, try to ask different levels of questions or open questions; The arrangement of after-class exercises highlights the hierarchy and designs some problems for students with special needs to solve; In math reading, by designing "math stories", "Do you know?" "Mathematical Kaleidoscope" and other columns provide certain reading materials for students to choose to read; In the design of practical activities, different students can get different experiences on the premise of ensuring the necessary development of all students; Paying attention to the diversification of problem-solving strategies not only respects the differences of students' life experience and cognitive characteristics, but also provides a broader space for students to show their individuality. Through this open and flexible arrangement, the teaching materials strive to make different students have different development in mathematics.
For example, in the "Counting, Counting, Multiplying" unit in the first volume of the second grade, the textbook creates a "children's paradise" situation. Some children are riding electric small planes, some students are rowing boats, and some students are riding electric small trains. After students observe this situation, the textbook presents the column "Tell me about it": What math questions can you ask? This problem has great flexibility, and different students can put forward a variety of mathematical problems according to their own interests and ability to choose information. By exchanging questions with each other, students not only established the concept of multiplication, but also realized the connection between mathematics and daily life. At the same time, they showed their individuality in communication and gained different development.
(eight) combined with appropriate materials to reflect the cultural value of mathematics.
In recent years, attaching importance to the cultural value of mathematics in mathematics curriculum has formed a * * * understanding. Mathematics curriculum should not only help students learn and master mathematics knowledge and skills, but also help students understand the value of mathematics (including cultural value). This textbook tries to reflect the history, application and development trend of mathematics, the role of mathematics in the progress of human society and the development of human civilization, and the promotion of social development to the development of mathematics.
Textbooks embody the cultural value of mathematics in both explicit and implicit ways. On the one hand, the textbook provides students with examples about the role of mathematics in history, culture and the real world through columns such as "Mathematical Kaleidoscope" and "Do you know", and introduces some mathematicians' stories, mathematical anecdotes and mathematical historical materials in appropriate places, so that students can understand that the generation and development of mathematical knowledge stems from the needs of human life, experience the role of mathematics in human progress, and stimulate students' interest in learning mathematics. On the other hand, in the study of part of the content, the teaching materials extensively explore its various applications in the real world, so that students can realize the great role of mathematics in human society and the mathematical value contained in it.
For example, in the content of "Symmetry, Translation and Rotation" in the second volume of Grade Three, the textbook shows the application of graphic transformation in many aspects, including China traditional folk art-paper-cutting, Peking Opera masks, musical instruments and textiles, the symbol of the capital-Tiananmen Gate and the Palace of the Forbidden City, the magical natural world-butterflies, insects and leaves, and the mirror symmetry phenomenon in daily life. Multi-angle materials and colorful displays fully reflect the role of mathematics in human civilization.
Second, the basic content of teaching materials and the characteristics of various fields
In the arrangement of specific content, the textbook strives to strengthen the core concepts and ideas of primary school mathematics, and pays attention to developing students' sense of number, symbol, space, statistics, application and reasoning ability; Strive to "return to simplicity", highlight the essence of mathematics learned, reflect the basic process of mathematics learning, and the position and role of mathematical thinking methods in solving problems; Broaden students' learning space, and select rich contents including numbers, operations, space, graphics, data, possibilities and relationships, so that students can appreciate the whole picture of mathematics as soon as possible.
This textbook adopts the method of mixing the contents of number and algebra, space and graphics, statistics and probability, practice and comprehensive application, that is, the contents of the four fields are arranged in one textbook at the same time. The content of each field has the following characteristics.
(a) the field of numbers and algebra
The content of number and algebra plays an important role in the mathematics curriculum of compulsory education and has important educational value. Compared with traditional textbooks, this textbook emphasizes the significance of making students experience, feel and understand numbers and operations through actual situations, emphasizes the development of students' sense of numbers, and pays attention to cultivating students' consciousness and ability to solve practical problems by using numbers and operations.
Understanding of 1 figure
Number is the basic content of mathematics learning, which has important significance and function. Numbers can be used to represent the number of a set, the order of a group of things, and the results of measurement ... Especially in the digital modern society, numbers have become an important means for people to express, communicate and transmit information. In the process of learning numbers, students should understand the various meanings and functions of numbers in the process of acquiring the concept of numbers.
(1) Pay attention to the process of abstracting numbers from the real world and understand the meaning of numbers.
Whether it is integer, fraction, decimal or negative number, it is a summary of human life practice and is closely related to solving practical problems. Therefore, the textbook attaches great importance to the connection with the real world, trying to reveal the process of abstracting numbers from the real world and highlighting the model role of numbers.
For example, in the first volume of Grade One, "Numbers in Life", the textbook presents a "lovely campus", which creates a very childlike situation for the opening of an animal school and asks, "Can you count how many rabbits there are?" Encourage students to observe by themselves, abstract "number" from the specific number of things, and realize that number has the meaning and function of expressing the number of objects. Take a walk on campus and talk about what there is and how much there is. Let students feel the close connection between mathematics and life and further understand the corresponding relationship between numbers and things. The situation of "Happy Home" enriches students' understanding of what numbers represent and makes them realize the role of numbers as models.
The textbook also emphasizes students' understanding of the meaning of numbers in actual situations and hands-on operations, such as the meaning of cardinal number and ordinal number, counting one by one, the composition of numbers, the meaning of numerical system and so on. Among them, the concept of value system is very important. Learning it should not stop at remembering the names of numbers and knowing how to read and write numbers, but should focus on the leap from counting one by one to grouping numbers, thus developing students' real understanding of the value system. For example, in the unit "Numbers in Life" in the second volume of Senior One, the focus of the textbook is to let students experience the process of expressing numbers in an appropriate way. In the activity of showing how many beans there are in a handful, the question of "how to dial and how to write" is designed to encourage students to show how many beans there are. In order to see the number of beans conveniently, students will realize the necessity of using larger units (10, 100) and understand the significance of the value system. At the same time, the textbook also designed an activity to see who counts fast, and you dial me to write, and divided the numbers into ten and first-class activities, so that students can further understand the value system.
Another thing to note is the processing of "decomposition and synthesis of numbers within 10". In traditional textbooks, before learning "addition and subtraction within 10", we need to learn "decomposition and synthesis of numbers within 10", and take the decomposition and synthesis of numbers as the operation of addition and subtraction. This practice is problematic. The decomposition and synthesis of numbers are essentially the same as addition and subtraction. Therefore, this textbook does not take the synthesis and decomposition of numbers within 10 as the logical starting point for learning addition and subtraction, but directly combines the process of learning addition and subtraction with the process of solving problems from students' life experience, so that students can personally experience the process of abstracting addition and subtraction formulas from problem situations and explaining and applying them, thus understanding the significance and application value of addition and subtraction. This is not to ignore students' experience of the composition of logarithm, but to combine logarithm with addition and subtraction, deepen students' understanding of the composition of logarithm and develop their sense of number through problem-solving activities and interesting games. For example, when I was studying "the addition of eight" in the first volume of senior one, the textbook created a game of "skipping rope". Students can observe from the theme map: 1 * * There are 8 children skipping rope, of which1children wear hats and 7 children don't; There are 2 children rocking rope and 6 children skipping rope; Three children wear skirts and five children wear pants; Four children are boys and four children are girls. In the actual situation, students not only experienced the composition of 8, but also deepened their understanding of the meaning of addition. Moreover, this question is very interesting for students and cultivates their ability to obtain information from charts.
(2) Being able to grasp the relative size relationship of numbers in specific situations and pay attention to the feelings of large numbers.
Comparing numbers is an important part of mathematics learning. Textbooks do not simply compare the size relationship between two abstract numbers, but provide rich materials for students to master the relative size relationship of numbers in specific situations, which is an important aspect of developing students' sense of numbers. For example, in the unit "Numbers in Life" in the second volume of Senior One, the textbook pays special attention to students' description of the relative size relationship between numbers in their own language, such as describing the size relationship between 85 chickens, 42 ducks and 34 geese (within 100) in language. It can be said that the number of chickens is much more than that of ducks, and the number of ducks is more than that of geese.
A survey shows that big data often appears in newspapers and magazines, but students lack a lot of experience. In order to make students better understand the information of large numbers, better adapt to daily life, understand the meaning of numbers and establish a sense of numbers, the textbook arranges the feelings and expressions of large numbers, and focuses on encouraging students to use familiar things around them to estimate large numbers from all angles. For example, the textbook has designed a variety of activities from the perspectives of length, area, volume, time and quality, encouraging students to feel tens of thousands and hundreds of millions of such big numbers from multiple angles.
(3) Be able to express some things in daily life with numbers and communicate with them.
Numbers are the most effective means for people to express, communicate and transmit information in modern society. From the international code transmission of military intelligence, economic information and scientific and technological trends, to the representation of telephone number, postal code, vehicle number and ID number, to student number and room number, it can be said that numbers are everywhere. Therefore, the textbook encourages students to use numbers to express some things in daily life and communicate with them. For example, the textbook has designed practical activities to encourage students to investigate how the class number, hotel room number, telephone number and ID number are arranged, so as to code each student in the school, and it is required that from the code of each student, we can see which grade and class the student is in, which year he entered school, and whether he is male or female. For another example, in the "percentage" study, students are required to investigate and estimate the percentage of boys, students who write with their right hands, students who wear glasses, students who like sports, and students who come to school today, so that students can feel the wide application of percentage in their lives.
2. Digital operation
The mathematics curriculum in our country has always regarded the operation of numbers as the main content of primary school mathematics, attached importance to cultivating students' operation ability, and achieved many excellent results and valuable experience. However, for a long time, some people's understanding of computing ability is not comprehensive, and they just equate it with computing skills (that is, computing is correct and fast), and because of exams and other reasons, the requirements for computing difficulty and speed are getting higher and higher. On the other hand, with the development of information technology, do students still need to calculate such a difficult problem and calculate it so fast? Basic computing skills are of course necessary, but what is the "basic" standard? Should students focus on other valuable content? What else is "valuable"? On the basis of in-depth thinking on these issues, the textbook pays attention to the following aspects in the operation content of numbers: