1. Understand the generation of counting units and numbers, further understand the counting units and numbers of ten thousand levels, and master the number sequence table containing ten thousand levels and ten thousand levels; Understand the meaning of integers and be able to read and write integers correctly.

2. Contact the reality, initially perceive the size of the integer, and feel the practical application of the integer.

teaching process

First, know the counting units and numbers.

Through the choice of time unit and area unit, it shows that people need to choose the appropriate measurement unit according to the specific situation when measuring and calculating.

Teacher: Use counting units when counting. Do you know what counting is? (I don't know)

Teacher: Simply put, counting is counting. (Showing pictures of stone counting) Human ancestors once used stone counting, such as catching 1 sheep, represented by 1 pebble; This ancestor caught a lot of sheep (student laughs). What shall we do (show the big stones)

Teacher: Guess, what does this big stone mean? (1 10) Like one, ten is the unit of counting. What if ten is not enough? (expressed in hundreds) Is 100 enough? (Thousands)

Teacher: One, ten, hundred and thousand are the counting units we have learned. (blackboard writing: one, ten, hundred, thousand)

Display: 4 small stones and 2 big stones. Small stones are in front, big stones are behind.

Teacher: What numbers do these stones represent? (24) Why not 42? Four pebbles are in front of two big pebbles.

Health: 1 the big stone is 1 10, two are two tens, and four pebbles are four ones, which adds up to 24.

Teacher: Yes! When counting, the position of the counting unit is specified. For example, the position of the counting unit 10 must be in front of the counting unit 10. The location of the counting unit is called a number. For example, the number of the counting unit 1 is a number. What about the number where ten is? What about hundreds and thousands? (The blackboard corresponding to the counting unit: unit, ten, hundred, thousand)

Second, know the counting unit of ten thousand levels

Teacher: We know that one, ten, hundred and thousand are all units of counting, and their digits are one, ten, hundred and thousand respectively.

The results show that the output of sugarcane in China in 2003 was 90.24 million tons; In 2003, the output of rapeseed in China was11420,000 tons. Who can understand these two sentences? Few students raise their hands. The first student can't read it, the second student can read it accurately, and the third student can read it loudly and accurately.

Teacher: Do you want to know how to pronounce these large numbers? Want to read as well as these two students? (Students nod frequently) Today, let's count together. (Revealing the theme: Identifying Numbers)

Teacher: What is the unit of counting greater than one thousand? How much is 10 thousand? (Ten thousand is ten thousand)

Teacher: What do you think of ten thousand? What is the (very large) unit of counting greater than ten thousand? (one hundred thousand)

Display: a cuboid of 100 10 100 arranged by 65438 small cubes. (Students can't help exclaiming)

Teacher: What is bigger than100000? What about those larger than a million? We can't adapt to this screen. Can you imagine? (Students can't help but close their eyes and imagine and keep exclaiming)

Teacher: Counting units greater than one thousand are ten thousand, one hundred thousand, one million and ten million. What are their numbers?

Student: Ten thousand, one hundred thousand, one million, ten million. (camera blackboard)

Teacher: Is there a bigger counting unit? A: Yes. Several students also said hundreds of millions) Yes, there are many more. (Write tens of millions before ellipsis on the blackboard, tens of millions)

Third, integer writing teaching

1. Know the number on the counter.

Teacher: Just now we used a small cube to represent the counting unit, which was too troublesome. Fortunately, we have a counter. (Displays a four-digit counter) Is a counter enough? (Not enough) Then we can use two (combining two counters into one counter).

Teacher: What's on the left of a thousand people? (Students read 10,000, 100,000, 1 million and 10,000 respectively)

2. Write a five-digit integer.

Teacher: (Dial 1 bead on the ten thousand digits of the counter) What does this mean? (ten thousand)

Continue to leave 2, 3 and 4 beads on the 10000-bit counter, and students will read 20000, 30000 and 40000 in turn.

Teacher: Can you write? Write the number of 40 thousand.

Teacher: How did you write it?

Health: Write a four first, and then four zeros. (blackboard writing: 40 000)

Leave 5, 6, 7, 8 and 9 beads at 10000 positions respectively. Students read in turn and write 70,000 and 90,000.

3. Feel the meaning of Wan Series.

Teacher: When we write 40,000, we write 4 first and then 4 zeros. What does (4/40,000) 4 mean? (40,000)

Teacher: (referring to 7 over 70,000 and 9 over 90,000) What does 7 mean? How about nine o'clock? (70,000,90,000)

Teacher: What do these figures have in common? (The last four digits are all zeros) Why?

Health: All the beads are placed on thousands, and there are no beads on thousands, hundreds, tens and digits, so they are represented by 0.

Teacher: Yes, when there are no beads on a number, just write 0 as a placeholder! When writing tens of thousands, what should I write first?

Health: Write that number first when you write tens of thousands.

Teacher: Oh, just write tens of thousands first. Write again (four zeros)

4. Write a six-digit integer.

Teacher: (dial 90,000 yuan 1 pearl) and then dial 1 pearl.

Health: Ten into one, 10 Ten thousand is one hundred thousand.

100000 seats up and down 1 0 pearl, 1 00000 seats up and down 1 pearl,10000 seats up and down1pearl. The students answered 1 1 ten thousand.

Teacher: Can you write this number? (Students write numbers) How to write?

Health: Write 1 1 first, and then write four zeros. (blackboard writing: 1 10 000)

Help students who make mistakes find out the reasons and correct them.

Continue to dial the beads in those ten thousand places. Students read120,000,130,000,140,000 and150,000 in turn and write150,000.

Teacher: (while talking, dial the beads) 10000 dial 9 beads, 100000 dial 9 beads. Can you write?

Health: Write 99 first, and then write four zeros.

Teacher: What does the number 1 1 1599 mean? (1 1 ten thousand,1fifty thousand, 990 million) How do you write these figures?

Health: Write as many as 10,000 first, and then write four zeros.

Teacher: These numbers all represent tens of thousands, and such numbers are integer tens of thousands. What are the characteristics of tens of thousands?

Health: There are four zeros at the end.

5. Write an integer of seven or eight digits.

Teacher: On the basis of 990,000 yuan, dial another pearl. how much is it? (one million)

Funding for teacher-student cooperation1000000,10/00000, write numbers.

Teacher: It seems that if you want to write integers correctly and quickly, you need a checking method. How to check?

Health: There are four zeros at the end.

Teacher: We can separate these four zeros from the previous numbers (draw a score line on 1 0 10 000) and check whether the numbers are written correctly in this way.

First, dial 6.5438+0.99 million on the counter for students to read and write, and then dial from1960,000 to1990,000 for students to read.

Teacher: Now the counter is 6.5438+0.99 million. How much is the other bead? (2 million) Yes, ten into one.

The teacher continued to pluck the ball at the counter, and the students read 2,012,060,000 in turn, and wrote down 2,060,000 to guide the students to draw lines for inspection.

Exhibition:100000 plot, from 9.6 million to1020000.

Teachers and students play with beads, read, write and proofread.

Fourthly, introduce several levels.

Teacher: Just now we divided these integers into two parts, followed by four zeros. What do the previous numbers mean?

Health: How many tens of thousands.

Teacher: How many tens of thousands do these figures represent? According to China's counting habit, starting from the right, every four digits are one level. Units, 10, 100, 1000 are grades, 1 10,000,110,000,110,000 are grades. Just separating a series from 10 thousand series is actually grading the integer 10 thousand, and the dotted line drawn is called grading line.

Teacher: Tens of thousands of numbers mean (tens of thousands) 10 1 000, which means (10/10,000).

Fifth, integer reading teaching.

Teacher: Large numbers are easy to be mispronounced, so it is not easy to mispronounce them by separating the 10,000 grades from the 10,000 grades.

When you finish thinking about doing the third question, you need to grade the integers first, and then look at them and compare them. (Students read correctly)

Teacher: Since let's read and compare, what did you compare in the process of reading?

Health: Read the number 10,000 first, and then add a 10,000.

Teacher: (850,000) What's the connection between the number of students studying in Grade 10,000 and our previous reading methods? Why do you want to add 10 thousand?

Health: If you don't add 10,000, it will become 85.

Teacher: Yes, what level has it become? How many tens of thousands are represented by the number of tens of thousands, so you should add a 10 thousand word when reading.

Sixth, feel the size of the integer.

Teacher: There are many large numbers in life. (Showing picture: Nanjing Olympic Sports Center Gymnasium has 60,000 seats)

Student books.

Teacher: How big is 60 000? How many people are there in our class? (46 people) Even if there are 50 people, do you know how much such a class needs to fill the gymnasium? When the students worked out the result, they were all surprised. )

Show: 100 000 How high are the sheets stacked together?

Teacher: Guess how high this pile of paper is? Students express different opinions and guide them to get the results through calculation.

Display: (1) Tiananmen Square is the largest city square in the world, covering an area of 400,000 square meters.

The Summer Palace is a famous garden in Beijing, covering an area of about 2.9 million square meters.

Students read and feel the actual size of numbers through communication.

Show me the first two numbers. Teacher: Can you read it now? (Let students who can't read at first read)

Seven, comprehensive exercises

Teachers and students cooperate, dial beads and write numbers as required. When the teacher says "request", say the name of Pearl and dial the number as required, and other students write down the numbers.

Teacher: Learning integers can help us to know more.

Show: (1) About 65 million years ago, dinosaurs became extinct, and the reason is still a mystery. (2) There are about 700,000 confirmed insect species in the world. (3) According to the statistics of UNESCO, about 60,000 species are extinct every year. (4) Air pollution Every year, about 300,000 to 700,000 people die prematurely due to smog pollution, and 25 million children suffer from chronic pharyngitis.

Students should be able to read and write numbers and educate students on environmental awareness in time.

Eight. Class summary

Teacher: What did we learn today? What's the problem? (No) Teacher, here are two questions. If you are interested, you can go back and find out.

1. According to China's counting habit, it is necessary to count in different levels. What habits do western countries use to make statistics? Please learn about this knowledge through after-class visits or reference materials, and communicate with your classmates.

2. What should I do if the quantity is too large and the counting unit is not enough?

Self-examination/introspection

1. It is not easy for fourth-grade students to understand the concepts of counting units and numbers. Calculate is calculate, and students don't know. To understand the counting unit, you must start with counting; To understand numbers, the counting unit is the basis. I once read a report that archaeologists found a sealed pottery jar when excavating an ancient tomb, but after opening it, it was some round stones of different sizes. It is found that these stones are used for counting, and the figures represented by the stones represent the wealth owned by the tomb owner before his death. This gives me great enlightenment: stone counting, a mathematical historical material, is an excellent material to help students understand the counting unit. In teaching, students can organize their own counting activities in the order of counting, counting units and numbers. A problem that has been bothering me for a long time was unexpectedly solved by an archaeological news. It is really a natural article, and it is a wonderful hand.

2. When students learn to recognize numbers in the third grade, they already have a preliminary understanding of Wan and can read and write 10 000 correctly. This is the basis for students to assimilate new knowledge by using the existing knowledge structure, and it is also the teaching starting point of this class. In teaching, by reading and writing five-digit integers, students naturally feel that if they want to write tens of thousands, they must write a few first and then add four zeros. In this process, what teachers should do is to help students clarify this feeling, guide students to read and write six-digit integers correctly by analogy, and gradually abstract this clear feeling into the writing of integers. At the same time, use this method to correctly read and write integers with seven or eight digits.

The teaching focus of this course is the writing of five or six integers, which is the basic material for students to explore and understand the law of integer writing. The more you are in the foundation, the more time you spend. Only when the foundation is figured out and thought through, the following study will get twice the result with half the effort. In teaching, I designed activities such as dialing, writing and reasoning on the counter to guide students to understand and master the writing of integers through independent thinking and communication. In this way, the knowledge and experience gained by students in autonomous activities are highly reliable and transferable.

3. Comprehension in writing and application in reading. For students, reading is more difficult than writing, because reading is first to grade the whole tens of thousands of numbers, and grading is an operational behavior based on understanding the meaning of tens of thousands of sequences. Therefore, students write numbers, teachers ask questions, and constantly feel the meaning of 10,000 series, which is the basis for students to understand grading. After understanding the grading knowledge, through the study of integer reading method, it is constantly applied in the reading process to further deepen the understanding of 10 thousand series. In teaching, I strive to provide a good environment and conditions for the development of students' cognitive structure. According to the logical relationship between students' existing cognitive development level and knowledge, I carefully designed the teaching process to facilitate students' understanding and learning and achieve the goal of conscious transfer.