Lecture Notes on the Meaning of Fractions 1 1. Talking about Teaching Materials
The meaning and writing of percentage is the content of unit 5 in the first volume of grade six.
1, teaching material analysis
Percentages are taught on the basis that students have learned integers and decimals, especially the meaning and application of fractions. Percent meaning is the extension of fractional meaning, and it is the basis of studying the application of percentage in the future. Learning the meaning of percentage helps students to better understand the practical problems such as interest rate, profit and discount in life. Percentage is widely used in practice, so this part is one of the important basic knowledge in primary school mathematics. Only by understanding the meaning of percentage can we correctly use it to solve practical problems in life.
2. Analysis of learning situation
Students are no strangers to percentages. They have been exposed to percentages more or less in their lives and can read them correctly. However, most students' knowledge and understanding of the meaning of percentage is not very accurate, and the difference between percentage and score is even more unclear.
3. Teaching objectives
(1) Knowledge and skills: enable students to understand the meaning of percentage, read and write percentage correctly, understand the difference between percentage and score in meaning, and apply percentage to solve simple practical problems.
(2) Process and method: Let students go through the process of collecting and analyzing information, and cultivate the ability of analysis, comparison and synthesis.
(3) Emotion, attitude and values: Combining with relevant information, make students realize the close relationship between percentage and life and understand the application value of mathematics.
4. Teaching emphases and difficulties
Teaching emphasis: understand the meaning of percentage.
Teaching difficulties: the connection and difference between percentage and score.
5. Teaching preparation
Ask students to collect relevant percentage materials from books or life before class; Teachers prepare multimedia courseware.
Second, oral teaching methods and learning guidance.
Teaching methods: Mathematics curriculum standards emphasize providing students with opportunities to fully engage in mathematics activities and exchanges based on their life experience and existing knowledge background, so that they can truly understand and master the basic knowledge, ideas and methods of mathematics in the process of independent exploration, and at the same time gain rich experience in mathematics activities. Therefore, in the teaching of this course, I always rely on the prototype of life to achieve re-creation. Select materials related to students to guide students to know percentage, understand the meaning of percentage, and feel the application value of percentage in life.
Learning methods: Teachers should not only teach students knowledge, but more importantly, teach students how to acquire knowledge. In this class, students can explore, study and communicate independently. The purpose is to cultivate students' preliminary generalization ability, problem-solving ability and self-study ability.
Third, talk about the teaching process
(A) information exchange, introducing topics
1, students show the survey data before class.
Tell me where these materials were collected. Is it easy to find?
2, courseware display diagram
The teacher pointed out that numbers like 18%, 50% and 64.2% ... are called percentages.
3. Ask questions and introduce topics.
The students are really good. Looking for so many percentages, it seems that percentages are widely used in life. People like to use percentages very much. What are the advantages of using percentages? What do you mean by percentage? Then, the topic was introduced and written on the blackboard: the meaning and writing of percentage.
(2) Explore independently and understand the meaning of percentage.
1, explore the meaning of percentage
(1) courseware drawing
What is the specific meaning of percentage in the picture?
When students understand the meaning of percentage independently, they are most likely to use the existing fractional knowledge, and they are also most likely to use the method of "1" to understand the meaning of percentage. At this time, the teacher should clearly point out: 18% is the result of the comparison between "Who" and "Who"? Who's who's 18%? Let the students know that "18%" here means "the number of nearsighted pupils is 18∕ 100". Then guide the students to say: the number of junior high school students with myopia is 49 ∕100 of all junior high school students; The number of high school students suffering from myopia is 64, which is 2100 of all high school students.
② What do you find by comparing these three data? How do you know that?
Experience the advantages of percentage comparison and remind students to develop good reading habits and study habits.
(2) communicate the percentage collected by yourself and its specific significance (group communication)
(3) Discuss the significance of promotion percentage.
T: percentage represent that relationship between one number and another. Usually people refer to percentages as percentages or percentages. (blackboard percentage or percentage)
2. The connection and difference between percentage and score.
The percentage of (1) is similar to the number we have learned. Is that percentage exactly the same as the score? Look at the information below. Which score can be expressed as a percentage? Which can't be expressed as a percentage? Why?
① 75∕ 100 of 72 ∕100 liter is 54∕ 100 liter.
② A batch of rice is 50 ∕100t, 80 ∕100t has been sold, and 40 ∕100t has been sold.
(2) Observe and discuss the difference between communication percentage and score.
4. Percentage of self-taught reading and writing
(1) Read by yourself and think while reading: What should I pay attention to when writing percentages?
(2) Reporting and communication
① What is the name of this symbol "%"? (percent sign)
(2) Writing instructions: Write the numerator first, and then the percent sign (%). Focus on guiding the writing of percentage sign. The two circles of the percent sign should be smaller to avoid confusion with the numbers before the percent sign.
③ Reading instructions: read "%"(pronounced as%) before reading molecules.
(C) fun exercises, consolidate and improve
1, read the following percentage.
3.5%, 150%, 98%
0. 1%, 100%
2. Choose the appropriate fill in the blanks from the five percentages written in the above question.
(1) Now the speed of the train is the original ().
(2) 1 m is 1 km ().
(3) Due to the joint efforts of the whole class, the passing rate of this unit will definitely reach ().
(d) activity summary, reflection and publicity
Talk about what you have gained from this class. Can you express your feelings about studying this course in percentage?
Fourth, talk about blackboard design.
per cent
It means that one number is the percentage of another number, which is called percentage.
Percentage is also called percentage or percentage.
The Meaning of Fractions is the textbook of Lecture 2.
The meaning and writing of percentage is the teaching content of Unit 5 in the first volume of the sixth grade of the standard edition of mathematics teaching curriculum. The meaning and writing of percentage is taught on the basis that students have learned the meaning and application of integers and decimals, especially fractions. It is the basis of studying the application of percentage in the future. The meaning of percentage is an extension of the meaning of fraction, and learning the meaning of percentage helps students better understand the practical problems in life such as interest rate, profit and discount. The textbook first explains the percentage that is often used in life, so that students can initially know the importance of percentage, and then leads to the significance of percentage in connection with students' real life, and finally explains the reading and writing methods of percentage.
As for the percentage, students have accumulated some experience in life. How to activate students' relevant experience, make it mathematical in time, and let students complete the self-construction of percentage meaning is the key to this course.
Teaching objectives:
1. Show the life scenes and let the students know the percentage. Fully understand the meaning of percentage through independent and cooperative inquiry. Percentage of correct reading and writing. Understand the difference in meaning between percentage and score. Will use percentages to solve simple practical problems.
2. Cultivate students' ability of observation, comparison and generalization through the collection, analysis and processing of information. Let students learn to communicate and cooperate step by step, and initially establish a sense of self-reflection and innovation. Promote students' personality development.
3. Let students realize that mathematics comes from life and is used in life to stimulate the emotion of learning mathematics well.
Teaching emphasis: understand the meaning of percentage.
Teaching difficulty: Understand the connection and difference between percentage and score.
Theory and teaching method
"Mathematics Curriculum Standard" emphasizes providing students with sufficient opportunities to engage in mathematics activities and exchanges according to their own life experience and existing knowledge background, so that they can truly understand and master the basic knowledge, ideas and methods of mathematics in the process of independent exploration, and at the same time gain rich experience in mathematics activities. In this class, I mainly embody the following teaching methods:
1. Choose the situation related to students' life background to introduce new lessons, and provide rich, vivid and interesting resources for students to discover and explore mathematical problems. At the beginning of the new class, the percentage is deduced by connecting with specific examples in students' lives, and then students are asked to try to find out the percentage seen in daily life, so that students can feel the close connection between mathematics and daily life, realize that mathematics is everywhere in life, and in the above-mentioned teaching process, the reading method of percentage is guided by trends, thus establishing a preliminary perception of percentage.
2. Independent inquiry, cooperative discussion, guide students to think positively, and reflect students' main role. This lesson is mainly to let students explore and discover the rules through several pieces of information in the picture, understand the meaning of these specific percentages, and then sum up the meaning of percentages. Then, through a set of questions, let students discuss the difference and connection between score and percentage, and further deepen the meaning of percentage. Then ask how to express the two scores that can be rewritten as percentages in the above questions in the form of percentages, lead out the writing method of percentages, let students try to write, and put forward the matters needing attention when writing percentages. Finally, look at the 78-page percentage writing, which plays a demonstration role in teaching materials. After learning the relevant knowledge of percentage, the reasons why percentage is widely used in life are highlighted through discussion and comparison, which is convenient for comparison, thus illustrating the advantages of using percentage. This step-by-step teaching not only enables students to acquire knowledge and skills, but also pays attention to students' mathematical thinking, problem solving, emotional attitude and values.
Methods of speaking and learning
1, through students' independent exploration, independent learning and cooperative communication, gradually understand the meaning of percentage, and cultivate students' preliminary generalization ability and self-study ability.
2. Explore and solve practical problems with what you have learned, and cultivate students' ability to apply knowledge, analyze and solve problems and their initial innovation ability.
Say activity process
(A) create a situation and introduce topics
1, showing four pictures on page 77:
Teacher: Students, please look at these four pictures. Can you read the mathematical information on it?
Q: Where else have you seen such figures in your daily life? (Percentage of pre-class presentation and exchange collection)
2. Teacher: Numbers like 18%, 50% and 64.2% ... are called percentages.
3. Derive the reading method of percentage.
4. Show the second question.
Teacher (Quotation): There are percentages everywhere in production, work and life. Why do people like to use percentages so much? What are the advantages of using percentages? What do you mean by percentage? In this class today, let's study together. (blackboard writing: percentage)
(2) Independent inquiry to explain the meaning of percentage.
1, explore the meaning of percentage
(1) Show the first of the four pictures and tell me what the percentage in the picture means.
Teacher: What do the three figures in myopia rate mean?
(2) Communicate the percentage collected by yourself and its specific significance.
Teacher: Now, please take out the percentages collected before class and tell me what they mean in detail according to your own understanding of percentages. (Students communicate with each other)
(3) Summarize the significance of percentage.
Abstract: Percentage indicates the percentage of one number to another.
Teacher: It seems that percentage represents the ratio between two numbers, so percentage is also called percentage or percentage. (blackboard writing: percentage means that one number is the percentage of another number, also called percentage or percentage).
2. The connection and difference between percentage and score.
(1) (projection demonstration): Which of the following scores can be expressed as a percentage?
(1) A pile of coal is 97/ 100 tons, of which 75/ 100 is used.
2 47/ 100 meters is 50/ 100 meters of 94/ 100 meters.
Students observe first, then report and communicate.
(2) Can you tell me the difference between percentage and score according to your understanding?
Students discuss first, then report and communicate.
3. Teaching percentage writing
Mainly divided into three levels:
(1) Trial writing: rewrite the above two scores with the denominator of 100 into percentage form. (Rewrite by name on the blackboard)
Q: So, what should I pay attention to when writing percentages?
(2) Read page 78 of the textbook.
What's the name of this symbol "%"? (percent sign), when we write percentages, we should pay attention to the numerator first, and then the percent sign (%).
(3) Exercise: Write the following numbers. (Projection demonstration)
4. Benefits of using percentages.
Form: discuss the shooting percentage of three athletes to illustrate that it is convenient to compare with percentages.
(3) Application practice
1, judge. This paper mainly examines students' understanding of percentage, the difference between percentage and score, and reading methods.
(1) A fraction with a denominator of 100 is called a percentage. ( )
(2) Xiaohong's height 147% meter. ( )
(3)34% is read as 34%. ( )
(4) Girls account for 45% of the class. ( )
2. military parade information. Mainly to cultivate students' patriotic feelings and strong pride in the motherland.
Teacher: This year is the 60th birthday of the motherland. During the National Day military parade, the teacher collected some information like this:
(1) The iron flow is rolling and the momentum is like a rainbow. 30 equipment teams are about to be reviewed with a brand-new lineup. All the reading equipment was independently developed and produced by China, and 90% of the equipment made its debut, which concentrated on the latest achievements of national scientific and technological progress and technological innovation, and fully demonstrated the great achievements of China's national defense and military modernization.
(2) Agriculture is the foundation of the national economy. Relying on its own strength, China has successfully solved the problem of feeding nearly 2 1% of the world's population with less than 9% of the world's arable land, which is China's great contribution to human development.
What do you think of this information?
This game is exciting.
Teacher: Percentages are everywhere in our lives. Now let's relax and lead everyone to play a game of "guess, guess, guess".
(1) Guess percentage:
One shot at a time (100%); As sure as a gun (90%); One in a hundred (1%); Kill two birds with one stone (200%)
(2) Guess the idiom:
100% hit rate (one shot at a time); The survival probability is only 10% (narrow escape)
(4) class summary
1, meaning and writing of percentage;
2. Application of percentage;
3. Differences and connections with scores.