First, from concrete to abstract, let students experience the reading and writing process of numbers.
From perception to representation, from representation to abstract concept, from abstract concept to concept concretization, it is a cognitive process for primary school students to master concepts. According to students' cognitive rules, let students go through the process of "counting the number of specific things-telling the composition of numbers-pulling the beads on the counter to represent numbers-abstract numbers-writing and reading", and understand and master the reading and writing methods of numbers within 100, which is helpful for students to establish a good cognitive structure. In teaching, we should provide students with intuitive and perceptual materials such as sticks and counters, especially make full use of the number table on the counter to guide students to abstract numbers from sticks and counter beads, and highlight the specific position of each number to guide students to write and read. For example, in Example 4 on page 34 of the textbook, 24 pencils (2 bundles of 4 pencils) can be replaced by wooden sticks. With the help of counters, students can be guided to operate wooden sticks and experience the digital reading and writing process from concrete to abstract. Let the students count the sticks first, and feel that 24 sticks are composed of 2 bundles of sticks and 4 sticks (as shown in figure 1). Then, let the students talk about how the sticks are made up, and further understand that 24 sticks are made up of two 10 sticks and four 1 sticks. Then, guide the students to operate and put out 24 sticks with a counter. Inspire students to think while posing: which number should two bundles (that is, 20 bundles) be placed on the counter? On which digit of the counter should four be placed? After thinking, the students will practice dialing and dial 24 on the counter (as shown in Figure 2). Ask students to dial and dictate: two beads on the ten digits of two ten-dial counters and four beads on the one digit of four one-dial counters. So, how do you write down the numbers represented by beads on the counter? Students should be guided to write 24 in the corresponding position against the numbers on the counter (as shown in Figure 3), and students at the same table should be organized to evaluate it. Teachers should also demonstrate how to write numbers. On this basis, ask the students again: "Where are the numbers 24 and 2 written?" ? On which number is 4 written? How to read? "Please try to read this number and exchange reading methods. Finally, the teacher summed up: the number 24, in which 2 is in ten positions, indicating two tens, and 4 is in one position, indicating four ones, so 24 is pronounced as 24 (blackboard writing). This teaching process focuses on perception, experience and promotion from concrete to abstract, allowing students to experience learning activities such as counting, dialing, writing, reading, speaking and commenting, so as to better understand and master the methods of reading and writing.
Second, highlight the "number" teaching, so that students can establish the concept of numbers in reading and writing numbers.
Constructivist learning theory holds that understanding the basic principles can make the subject knowledge easier to understand, which is beneficial to memory and transfer. Numbers refer to the position occupied by each digit of a number. Correctly understanding the meaning of numbers and establishing the concept of numbers are the premise of correct reading and writing. In teaching, we should regard the concept of numbers, reading and writing as an organic whole, and guide students to understand and master the basic laws of reading and writing by establishing the concept of numbers. To establish the concept of numbers in reading and writing, teachers should make full use of the number table on the counter to help students establish the representation of numbers such as one, ten and hundred, and then establish the concept of numbers. For example, after teaching example 4, the two-digit exchange position of the number "24" in the example should be changed to "42", so as to guide students to think deeply about the number "42" against the digital table on the counter, discuss and exchange "what hasn't changed", and then ask students to dial 42 on the counter, talk about the composition of 42, and write and read 42. On this basis, the teacher summed up that the same number represents different numbers because of its different digits, thus deepening students' understanding of the meaning of different digits and helping students to establish a preliminary concept of numbers.
In order for students to establish the concept of numbers when reading and writing numbers, it is also necessary to help students understand the specific name of each number by consulting the counter and master its arrangement law skillfully. Only in this way can students get a complete understanding of the numbers within 100 from concrete to abstract, and establish a clear concept of numbers such as unit, tenth and hundredth. For example, in Example 6 on page 35 of the textbook, the teacher asked the students to dial the beads with a counter, first one by one, then dial 9 beads in each position and ask, "How many more did you dial?" 10 How much is it? How to use the beads on the counter? "Then, dial one by one in ten places, dial nine, and ask," What do nine beads mean? How many tens does the other dial? How to express 10 ten with beads on the counter? How to read and write? "Then let the students open their textbooks, try to write 100, and read softly. Teachers should also use courseware to show or demonstrate the writing method of 100 on the blackboard, so that students can compare their own writing with the teacher's and see whose writing is standardized, neat and beautiful. If the writing is not standardized and beautiful, ask them to rewrite it in the exercise book. On this basis, the teacher continued to guide the students to talk at the same table. What are the first, second and third numbers from the right? What is the number on each number? Fill-in-the-blank textbook page 35: From the right, the first place is (a), the second is (a), and the third is (a). Finally, guide students to summarize reading and writing methods. First, let the students write a few numbers freely in 100 and read them aloud. Then think about it: where did writing and reading begin? On the basis of speaking, guide the students to sum up: "Reading and writing should start from a high position. "Let students feel that what they say is the same as what the teacher said, and gain their own successful experience of summing up knowledge. At the same time, help students understand the meaning of "high position" in specific situations: if it is three digits, then the hundred digits are high positions; If it is a two-digit number, then the ten-digit number is high. This can promote the continuous improvement of students' reading and writing level.
Third, organize reading and writing exercises to develop students' sense of numbers.
In order to help students distinguish and remember numbers, when reading and writing numbers, students can dial numbers on the counter or read and write numbers with the help of counters or digital tables, or put digital cards in the digital tables to read and write numbers, or do reading and writing exercises without learning tools.
1 Look at the counter dial and read it. When giving example 5 on page 34 of the textbook, teachers can dial the following two numbers on the counter (as shown in figure 1 and figure 2), so that students can write before reading, and then organize a discussion: when there are no people (pearls) in a place, where should they use it? And asked, "where is the number 4 of the number 40?" What does this mean? Can the 0 in the unit not be written? Why? " On this basis, let students write and read the third number dialed by the counter (as shown in Figure 3), so that students can further understand that writing 1 on the hundreds and writing 0 on the tens and digits is 100, thus strengthening the occupation of 0, preventing the omission of 0 and deepening students' understanding of writing methods.
Look at the digital card reading in the digital table. Before class, let students prepare 0~9*** 10 digital cards. In class, let the deskmate cooperate. One person randomly selects two digital cards from 0 to 9 and puts them in the unit and the tenth place respectively (0 can't be placed in the highest place), and the other person reads the numbers. After reading a number, ask what the number on each number means. This interactive exercise with everyone's participation not only reflects the openness of exercise design, but also helps to mobilize students' learning enthusiasm.
3. Break away from intuition and strengthen comparative reading and writing practice. After students have done some writing and reading exercises with the aid of visual AIDS, they should be organized to do comparative exercises. In view of the mistakes that students easily make, we can design some comparative exercises, such as writing and reading numbers 6 and 60, 15 and 5 1, 47 and 74, 10 and 100, which will help students deepen their understanding of numbers and develop their sense of numbers.
Author unit
Fujian province Shanghang county teachers' further education school
Editor: Li Ruilong.