(A) the main points of knowledge teaching
1. On the basis of understanding the numbers within ten thousand, further understand the new counting units of ten thousand, one hundred thousand, ten thousand, ten million and one hundred million.
2. Know the name of each counting unit within 100 million and the relationship between two adjacent units.
3. Master the numerical sequence table within 100 million and the method of reading step by step.
(2) Key points of ability training
Numbers within 1 .100 million can be read correctly according to several levels.
2. Help students to establish the concept of number, master a series of counting knowledge, and cultivate their analytical and comprehensive abilities.
3. On the basis of reading within 10 thousand, teach reading within 100 million to cultivate students' transfer ability and analogy ability.
(C) moral education penetration point
Highlight the four-level counting method in China and encourage students to study and create in the field of science.
Teaching emphasis: reading numbers within 100 million.
Difficulties in teaching: there are numbers of 0 at the end and middle of each level.
Preparation of teaching AIDS and learning tools: abacus and projector.
Teaching step
First, pave the way for pregnancy
1. Answer: (1) One thousand has () a hundred, and ten thousand has () a thousand.
() One hundred is one thousand, and () one thousand is ten thousand.
2. Review the numerical order within 10,000.
The teacher shows five cards: one, ten, one hundred, one thousand and ten thousand. First, the teacher posted "Hundred" on the blackboard, and named the students to post other cards in turn. After all the stickers are posted, please dictate the numerical order within 10 thousand.
3. Reading practice:
The teacher fills in the numbers below the pasted numbers, and the students do reading exercises. Focus on guiding students to review the reading of numbers with 0 in the middle or at the end.
4. Think about it, what are the rules for reading numbers within 10,000?
Guide the review of reading methods for numbers within 10,000, and pave the way for reading methods for numbers within 100 million. )
Second, explore new knowledge.
(1) projection demonstration:
① 1993 the population of Taiwan Province province is about 20,944,000.
The speed of the artificial earth satellite is about 474,000 meters per minute.
(3) A county tried to plant new rice varieties last year, with a total increase of 547 1 10,000 kg and an increase of 6.705 million yuan.
Students can read the above three sentences freely.
We have learned the numbers within 10000, and we often use these numbers greater than 10000 in our daily life and production. Today, we will learn how to read these big numbers.
How to read numbers within 100 million?
2. Newly awarded:
(1) Teaching counting units are one hundred thousand, one million, ten million and one hundred million.
① Students observe blackboard writing: one, ten, one hundred, one thousand, ten thousand. Think about it: What are the rules between them? Can you keep counting down according to this law?
(Guide students to transfer and analogy on the basis of original knowledge, and cultivate the ability to acquire knowledge actively. )
Students count themselves according to the law that ten tens are one hundred and one hundred is one thousand ...: ten tens are one hundred thousand, ten hundreds are one million, and ten million are ten million.
Teacher writes on the blackboard: 100,000, millions, tens of millions.
② Understanding "100 million":
Using the method just now, let's count down. How much is ten ten million?
(Students who have cognitive difficulties may say that ten million is one hundred million. At this time, the teacher should count with the students and point out that one hundred million is "one hundred million". )
The teacher wrote on the blackboard: 100 million, and pointed out that 100 million is a big number. How big is it? Look at the projection:
Free reading. (Visualize abstract numbers)
(3) Combining blackboard writing, the teacher points out one, ten, hundred, thousand, etc. Are all counting units.
What are the counting units within 100 million?
What do you find between two adjacent counting units from the counting process just now?
Students discuss and report the results.
Guide students to make it clear that the progress rate between two counting units is 10, that is, the decimal relationship.
(2) Teach the list of numbers and numbers within 1 100 million:
① Guide students to observe: How are the counting units arranged?
The teacher explained that when using numbers to represent numbers, the counting units should be arranged in a certain order, and their positions are called numbers.
(2) Teachers and students * * * complete the numerical sequence table within 1 100 million.
Blackboard: Write a "bit" under each counting unit.
The key point is to add "……" before the billion digits.
③ Distinguish the connection and difference between numbers and counting units;
Guide students to make it clear that the unit of counting is one, the unit of counting is ten, and the unit of counting is ten million. Several ones are written in one place, several tens in ten places ... and dozens in ten million places.
The same number, written on different numbers, represents different counting units.
The teacher shows the card: the number "5", put it on different numbers, and the students say its counting unit respectively.
④ Understand the numerical score:
In order to read numbers within 100 million, China has always followed the four-digit counting rule, that is, every four digits from the right are one level. One, ten, hundred and thousand are levels, indicating how many "ones" there are; 10,000, 100,000, 1 million and 10 million are all 10,000 levels, which means how many "10,000".
Highlight China's four-level counting knowledge and infiltrate moral education.
The teacher writes on the blackboard and completes the numerical sequence table.
⑤ Feedback training:
Please carefully observe the numerical sequence table and complete exercises 1: 1 and 2. (display light)
(3) the teaching method of reading ten thousand books:
(1) Read the following numbers first:
28、308、4007、3070
What are these figures at? What does this mean?
If these figures are put at the level of 10 thousand, what does it mean
Guide the students to find out: How many "chess pieces" does the same number represent at each level?
How many "tens of thousands" do you mean by 10,000?
(Infiltrate the internal connection between personal series reading and ten thousand series reading. )
② Teaching examples 1:
The teacher allocated 280,000 yuan and 30.7 million yuan to the abacus with counting units respectively.
Students refer to the number table, write Arabic numerals first, and then try to read them by themselves.
Guide students to deduce ten thousand series of reading methods according to three series of reading methods.
The students reported the results of the trial reading to each other.
③ Feedback training: divided into 2 pages.
④ Thinking and discussion:
What are the similarities and differences between the 10 thousand series and the series?
Guide the students to make it clear: read the numbers in the 10,000-level according to the reading method of 10 series, followed by the word "10,000".
(4) Teaching includes ten thousand levels and three series of reading.
(1) Example 2:
Observation: What is the difference between Example 2 and Example 1?
(Example 1 is an integer, and Example 2 is two series. )
How to pronounce a number with two levels like this? Can you read these numbers with what you have just learned and what you have learned before?
② Students try to read the three numbers in Example 2.
24600 640700 10030040
Thinking and discussion:
Which level to read first and how to read it? What level and how to read it? When should you not read "0" and when should you read "0"?
(Try reading discussion to break through the difficulties: encourage students' spirit of unity and cooperation)
(3) On the basis of study and discussion, guide students to summarize the reading rules of numbers within 100 million.
④ Feedback training: divided into 3 pages.
Third, consolidate development.
1. Exercise 1 Question 3: Read the numbers in the following groups.
34 and 340000 3004 and 30040000
340 and 3400000 3040 and 30400000
Through this exercise, students can understand the relationship and difference between the number of levels and the number of levels in reading, and further understand the second law of reading. )
2. Exercise 1 Question 4:
Students speak and read aloud fully, facing the whole group, and guide students to read the numbers with zeros in the middle and at the end according to the reading rules.
3. Judges:
(1)40805000 in words: four million eight hundred and fifty-five thousand yuan only ()
(2) Do not read all zeros in the number 3706000. ( )
(3) There is a zero in the number 40506000 to be read. ( )
This question examines students' mastery of difficult points. )
4. Show the activated digital card and do reading exercises on the digital sequence table:
Fourth, the class summarizes.
What's your new understanding of logarithm through this lesson?
Homework: Exercise 1, Question 5.
Guide the students to summarize what they have learned in this lesson in their own language.