Week: the first 1 1 week
School: Six primary schools (central primary schools) Two spare teachers: Li Meichong Lecturer:
First, teaching material analysis:
(1) The position and function of textbooks
Percentages are taught on the basis of students' study of integers. Percent is actually a number indicating how many percent one number is in another. Therefore, this part is one of the important basic knowledge in primary school mathematics.
2. Compilation of teaching materials.
The purpose of teaching and drawing the concept of percentage with the flavor of the times is to guide students to understand the meaning of percentage and the application value of numbers in real life.
Second, the focus and difficulty of the textbook
Key point: correct reading and writing percentage.
Difficulty: Understand the connection and difference between percentage and score.
Third, the target preset
1, connecting with real life, so that students can understand and master the meaning of percentage. Students understand the connection and difference between percentage and score. 3, can read and write correctly.
Fourthly, the analysis of learning situation.
Percent and fraction are two abstract concepts. Because of the percentage of students' first contact, it is necessary to master the connection and difference between them.
The Key Points and Difficulties in verb Teaching (Verb Abbreviation)
1, understand the meaning of percentage.
2. Let students understand the connection and difference between percentage and score through discussion.
Sixth, the teaching process.
First, review.
1, Children's Palace * * * exhibits 400 scientific and technological works of primary and secondary schools. Among them, only primary school students' works accounted for 150. What percentage of primary school students' works account for the total number of exhibits?
I hope primary school students will take part in the national painting competition. * * * Children draw 823 and children draw 504. What is the proportion of children's paintings in the total number of entries?
Question: What are the characteristics of these two questions?
How to find how many times one number is another?
Second, the new curriculum teaching
1, contact the actual percentage.
(1) Show four pictures on page 77 of the textbook.
Teacher: Like 18%, 50%, 64.2% ... We all call it percentage.
(2) After previewing, collect the percentage of life extensively. )
2. The significance of teaching percentage.
(1) Question: Can someone tell us the specific meaning of the percentages in the four pictures just now?
Teacher: Percentages are usually not written in the form of fractions, but expressed by adding a percent sign "%"after the original molecules.
The teacher demonstrated a percentage and asked each student to write down another percentage in his notebook.
Remind students that when writing a percent sign, two circles should be smaller to avoid confusion with numbers.
(2) The percentage of reading teaching.
Let the students say how to read percentages.
2 summary: the reading method of percentage is basically the same as that of score, so read the denominator first.
5. practice.
(1) Complete the 1 question of "doing".
Ask the students to write down each percentage.
Question: What should I pay attention to when writing percentages?
(2) Complete the second question of "doing".
Ask the students to read each percentage.
Question: How to pronounce the percentage?
(3) Complete the third question of "doing".
Teacher's summary: The difference between a score and a percentage is that a score can not only represent the proportion of numbers, but also represent a specific quantity.
Third, consolidate the exercise: complete the exercise 18, topic 1-4.
Fourth, the class summary
Today, we learned percentage. Please use "percentage". What is the percentage?
In this class today, we have entered the world of percentage and opened the door of percentage. The world of color percentage will definitely appear before our eyes. I hope you can learn the percentage from here, ok? Finally, the teacher sent you a famous saying to encourage you.
Genius =99% sweat+1% inspiration.
Verb (abbreviation for verb) assigns homework.
1, write the following percentage.
Forty percent, 24.700, 12.1 thousand.
2. Read the following percentage.
8% 15% 7.5% 240% 12 1.3% 100% 200% 16.03%
3. True or false.
(1) The number of chickens is 80% of that of ducks. ( )
(2) A pile of coal weighs 80% tons. ( )
4. Choose an appropriate percentage to fill in the blanks.
2% 15% 120% 98% 100% 0.000 1%
(1) In class today, students who raised their hands actively accounted for () of the class.
(2) The speed of the car is the speed of the truck ().
(3) As long as the students study hard, the pass rate of this unit will definitely reach ().
(4) The possibility of finding a needle in a haystack is ().
5. Write percentages in idioms.
Kill two birds with one stone () for a hundred years ().
With a grain of salt () Nine times out of ten () Get twice the result with half the effort ()
Win every battle () Get twice the result with half the effort ()
Teaching content: 80 pages of teaching materials about percentage and decimal exchange.
Teaching material analysis: (1) Location of teaching materials.
This part of the content is that students have learned the meaning of percentage, made clear the percentage, fraction and rate, and turned the calculation result into percentage, laying a foundation for calculation and application.
(2) the intention of compiling teaching materials:
The textbook does not give the method of mutual transformation first, but directly puts forward: how to transform numbers and decimals? Let the students explore by themselves, and then find the law of mutual transformation through comparison, so as to find out the quick method of mutual transformation.
Example 1 Teaching converts decimals into percentages. The textbook gives three decimals for students to explore, that is, the mother of the three decimals is the score of 100, and the process of converting the decimals into the score of 100 is written, such as1.4 =14/10 =10.
Example 2 Teaching converts percentages into decimals. The textbook asks, "How to convert the percentage of 27% into decimals? Let the students explore the methods of transformation. The textbook presents the students' thinking process: writing in the form of fractions, and then converting fractions into decimals through the method of converting fractions into decimals. Communicate your own methods.
The method of number mutualization. And let the students observe: What can you find? Guide students to discover the mutual variation law of numbers and further master simple mutual variation methods.
The focus and difficulty of the textbook:
The key point of the textbook: understand and master the reciprocal method of percentage and decimal.
Difficulties in teaching materials: find and summarize the methods of mutual transformation.
Analysis of learning situation:
Students have learned the reciprocity of decimals and fractions before, so it is difficult and meaningful. Fully activate students' original knowledge and prepare for the construction of new knowledge. After introducing the reciprocal method of percentage and decimal, on the basis of more practice, the reciprocal method of decimal is introduced.
Teaching emphases and difficulties:
Teaching emphasis: understand and master the reciprocal method of percentage and decimal.
Teaching difficulties: exchange percentages and decimals correctly and skillfully.
Target preset:
1 Convert percentages to decimals.
A successful experience. Number of times per week: 1 1 week School: Tuqiao Primary School, second standby, main standby teacher: Li Wenying teaching teacher:
Teaching process:
First, let's review:
1, divide the following decimal components into decimals, and talk about the method.
0.8 0.25 1.7
9/ 10 73/ 100 4/5
2. First, expand the number in the first line to 100 and reduce it to the original number1100. How does the decimal point move?
3.6 7 0.52
125 4 0.8
4. Write the following scores as percentages.
3/ 10 16/ 100 320/ 100
Second, explore new knowledge:
(a) talk about:
1 Today, we learn the reciprocity of percentages and decimals, which is in the process of statistical comparison and calculation in production and life. Next class, we will learn the reciprocity of percentages and decimals.
2. Preset question: What questions do you think of when you see this topic?
(1) How do percentages and decimals interact?
(2) Is the reciprocity of percentage and decimal related to the reciprocity of fraction and decimal?
Explore the method of converting decimals into percentages.
1, for example 1: convert 0.24, 1.4, 0. 123 into percentages.
2. Query method:
(1) Panel discussion: How to convert decimals into percentages?
(2) communication report:
(3) Evaluation of teachers' blackboard writing and summary methods:
Method 1: Combine the meanings expressed by several decimals in the example and convert them into percentages.
0.24 means 24%, so 0.24 can be directly written as a fraction with the denominator of 100, and then rewritten as a percentage.
Namely: 0.24=24/ 100=24%
1.4 means four tenths, which can be written as a fraction 14/ 10, and then written as 14/ 100 according to the basic properties of the fraction, and finally rewritten as a percentage:
Namely:1.4 =14/10 =140/100.
0. 123 means one hundred and twenty-three, which can be written as a fraction 123/ 1000, and the attribute 12.3/ 100, and finally rewritten as a percentage:
Namely: 0.123 =123/1000 =12.3/100 =12.3%.
Method 2:
1.4=4/ 10= 140/ 100= 140%
0.24= 24/ 100 =24%
0. 123= 123/ 1000= 12.3/ 100= 12.3%
Circle the calculation process and guide the students to think: what is the score without looking at the calculation process?
That is, converting decimals into percentages,
A few hundred semicolons will do. Important: If the decimal point moves two places to the right, the original number will be enlarged by 100 times and reduced by 100 times, so the size of the original number will remain unchanged.
3. Feedback exercise:
Convert the following decimals into percentages and talk about the conversion method.
0.97 0.08 0.005 0. 132 8
(C) explore the method of converting percentages into decimals.
1, Example 2: How to convert the percentages of 27% and 135% into decimals?
2. Try autonomous learning: let students observe from right to left. What if the fraction of 1 is converted into decimal? Have a try.
3. Exchange study income:
Can you use what you have learned to talk about how to convert percentages into decimals?
4. Evaluation and induction methods:
Method 1: First, according to the meaning of percentage, write the percentage in the form of fraction and convert the number into decimal.
Namely: 27%=27/ 100=0.27.
135%= 135/ 100=0. 135
Method 2:
Circle the calculation process and guide the students to think: what is the score without looking at the calculation process?
To convert percentages into decimals, just remove the percent sign. When the percent sign is removed, the original number will be enlarged by 100 times, and then the decimal point will be moved to the left by two places and reduced by 100 times. Therefore, the size of the original number remains unchanged.
5. Feedback exercise:
Convert the following percentages into decimals and talk about the conversion method.
97% 8% 0.5% 13.2%
(4) Simple methods to guide students to sum up percentages and decimals:
1, let students observe the results of Example 1 and Example 2 again, and find a simple transformation method of percentage and decimal.
For example:
0.97=0.97% 0.08 =8% 0.005=0.5% 0. 132= 13.2% 4=400% 97% =0.97 8%=0.08 0.5%=0.005 13.2%=0. 132 400%=4
2, find the law, summed up the simple reciprocity law:
(1 semicolon is enough.
(2) Yes.
Third, consolidate the exercises:
1. Complete the exercises 19 and 2 questions.
2. Judge the following problems and correct them.
( 1) 0.5.( )
(2)0.36 meters can be rewritten as 36% meters. ( )
(3)3.2%=3.2 ( )
(4)0.8=0.8% ( )
(5)2=200% ( )
3. Arrange the following two groups of figures in descending order.
3.3% 1/3 33.3% 0.33
Fourth, the class summary:
Teaching design of unit 5 "mutual transformation between percentage and score" in the first volume of sixth grade mathematics of People's Education Press
Week: Week 12 School: Tuqiao Primary School
Primary and secondary teachers: Teacher Liu:
First, teaching content: the relationship between percentage and score
Second, teaching material analysis
1, the position and function of teaching materials
The conversion between percentages and fractions is similar to the conversion arrangement between percentages and decimals. First, the number of components in the textbook is taught, and then it is easy before it is difficult, thus solving the difficulties. Explore, analyze, compare and summarize to cultivate students' thinking flexibility and abstract generalization ability.
2. The intention of writing this textbook.
Example 3: By solving the problem that "the students suffering from dental caries account for a few percent of the students in the whole school", let the students master the method of% composition, and at the same time carry out oral hygiene education for the students.
Example 4 thus mastered the method of dividing scores into percentages. In order to make students realize the diversification of problem-solving strategies, two conversion methods are proposed: one is to use the relationship between fraction and division to first convert fraction into decimal sum. The second is to expand or reduce the denominator of the fraction to 100 by using the basic properties of percentage and then write it in the form of percentage. These two methods are applicable to different situations, are universal methods and have a wide range of applications. The second method is simple, but in the method of 1, the textbook is 14.
3. Emphasis and difficulty of the textbook.
Key point: master the method of mutual transformation between percentage and score.
Difficulty: Understand the process of conversion between percentage and score.
Thirdly, the analysis of learning situation.
The students have mastered the reciprocal method of decimal and percentage. Generalization ability. Guide students to sum up and understand the methods to master the conversion between percentages, fractions and decimals, and make clear the relationship between them.
Fourth, the target preset
1.
2 series and differences.
Fifth, teaching is heavy and difficult.
Key points: master the method of conversion between percentage and score, and use it skillfully.
Sixth, prepare for the teaching process for the second time
(1) Import:
1, convert the following decimals into percentages.
0.7 1.25 0.379 2.27
2. Use decimals to express the following percentages.
50% 1 10% 33.3% 0. 1%
(B) Teaching implementation
1, learning percentage score.
① Example 3
② Question: What is the number?
Can you turn percentages into fractions? (thinking and trying)
(4) tell the rewriting process.
20 1804 blackboard writing: 20% = = 80% = =10051005.
⑤ Teachers educate students on oral hygiene and dental health.
⑥ Let students divide 0.5% into components. (cooperative discussion)
0.5 15 exhibition communication: 0.5% = =1001000200.
Question: What should I pay attention to when dividing percentages into components?
Let the students speak freely. The teacher concluded that when the percentage is divided into several numbers, it is written in the form of a fraction with the denominator of 100, and the price that can be reduced is simplest fraction;
⑦ Finish 8 1 page and do a bunch of 1 and 2 questions.
2. Percentage of academic achievement.
① Give three pieces of information of Example 4.
② Question: Can the score be expressed as a percentage? (Students try)
③ Group communication and feedback from the whole class.
144? 208 blackboard writing: = 0.2 = 20% = = 80% 555? 20 100
The teacher guided the comparison and came to the following conclusion: when converting the score into a percentage, you can first convert the score into a decimal, a percentage, or you can first convert the decimal part into a score with the mother 100, and then rewrite it into a percentage.
1④ feed back the third message and tell me how to convert it into percentage. 14
Let the students try the above two methods first: I find it difficult to divide it into decimals first, and the denominator 14 100 is also difficult. How can we do that?
Decimals, and then converted to percentages.
1 blackboard writing: =1÷14 ≈ 0.071= 7.1%14
⑤ Complete 82 pages and do 1.2. Page 83-84, questions 3-8.
Three. abstract
1, let the students talk about their gains.
2. Through exchange and induction, the "reciprocal method of percentage and score" is obtained.
Fourth, practice design.
1, divide the following scores into percentages:143139115108462.
100% 55% 1.6% 180% 0.8% 25% 280%
3. Turn the following fraction into percentage, and the percentage into component number. 711124% 8.2% 4454, at 6.8%, 0.603 0.63 60.3% 8 (), the smallest number is (), and the equal numbers are () and ().
The teaching design of "what percentage of applied problems" on page 90 of the first volume of sixth grade mathematics of People's Education Edition.
Week: Week 13 School: No.6 Primary School (Central School)
Primary and secondary school teachers: Wang Junmei's teacher:
Teaching content: experimental textbook, grade six, 90 pages, Example 2.
Second, teaching material analysis:
(1) The position and function of teaching materials
This kind of problem is actually a question of how many percent one number is of another, which can deepen students' understanding and ability of percentage.
(2) Writing intention
This example combines practical problems in life to teach the analysis and solutions of such problems. Then explain: the key to this kind of problem is to find the unit "1" and compare it with sleep (or less).
⑶ Analysis of academic status quo
Students have some learning experience in finding the percentage of one number to another, so the teacher of "1" should try to guide the division with "1" as the unit.
Third, the target preset
1. Enable students to connect with real life and know who is comparing with whom, and the comparison result is more (or less). Department.
Four, the focus and difficulty in teaching:
Key point: find out one application problem with more (or less) quantity than the other.
Difficulties: master the methods to solve this kind of application problems.
Five, teaching design:
A review question:
Last year, a township planned to afforest 12 hectares, but actually afforested 14 hectares. What percentage of the original plan was actually afforested?
Ask the students to discuss whether there is more planned afforestation or actual afforestation. How to answer this question if it is changed to "How many percent has Lin increased than originally planned"?
Change the review question to Example 2.
Today, we continue to learn how to solve problems with percentages.