The application of Bibi teaching plan 1 teaching content:
Hebei Education Edition Primary School Mathematics Sixth Grade Unit 2 Fifth Class (Application of Ratio)
Teaching objectives:
1, in the process of cooperative inquiry and problem solving, make students understand the significance of allocating a quantity according to a certain proportion, and master the characteristics and problem solving methods of allocating application problems according to proportion;
2. Cultivate students' ability to solve practical problems by using the mathematical knowledge they have learned, so that students can truly become the masters of the classroom;
3. Through examples, let students feel that mathematics comes from life and life cannot be separated from mathematics.
Teaching focus:
1, correctly understand the meaning of proportional distribution.
2. Master the characteristics and solving methods of proportional application problems.
Teaching difficulties:
Be able to answer the practical questions of proportional distribution correctly and skillfully.
Preparation before class:
Arrange students to preview.
Teaching process:
First, create a situation
1. Looking back at the average score learned before, the "fairness" of the average score leads to the unfairness of today's topic if it is still based on the average score. (Two people work together, but their shares are different, so the income distribution problem)
2. Summary: Just now, if the workload of two employees is the same, they should be allocated according to 1: 1, which is also called average score. If the completed labor share is different, it is unfair for them to distribute their remuneration according to 1: 1 What should I do?
(organizing communication)
Teacher: It is more reasonable to distribute the remuneration according to the share. In this way, an amount is distributed according to a certain proportion, which is usually called proportional distribution. (revealing topic: proportional distribution)
Second, the initial perception.
1, think about it, what proportion should the labor income of two people be distributed? (blackboard writing: allocated according to the completion ratio of 3: 2)
2. Who can say the specific meaning of 3: 2 in their own language?
3. Who can express how much each of them should get in a formula?
4. Summary: What did you learn from the life case just now? (What is proportional distribution)
Third, independent inquiry and cooperative learning.
1. Dialogue: In fact, there are many examples of proportional distribution like this in life. Have you seen them? Tell you one. Today, we will learn the content on page 19. As we have arranged a preview yesterday, we will communicate according to the following outline.
2. At this time, use PPT to show "learning content", "learning goal" and "guiding outline"
Learning content: Hebei Education Press, 19 page, the first volume of mathematics in the sixth grade of primary school.
learning target
1. Understand the practical problems of proportional distribution and master the solutions to such practical problems.
2. Understand the even ratio, and understand the significance of three quantitative even ratios.
Guiding outline
1 and example 1 What is the meaning of "the ratio of purple squares is 3:5"?
2. Talk to your classmates about the problem-solving ideas of each method in the example.
3. Can you draw pictures to understand these two problem-solving methods and communicate with your classmates?
4. How to understand the meaning of the sentence "Concrete is prepared according to 2: 3: 5" in Example 2?
5. The third question of "practice" is how to allocate 1200 kg of culture material.
Students carry out the following activities according to the guiding outline, teachers patrol, communicate with each group in depth, and pay attention to students with learning difficulties.
(1) Think independently and try to answer.
(2) group communication, talk about ideas.
(3) Organize communication and form ideas.
(4) Select appropriate content for pre-demonstration.
Fourth, focus on display
1 and example 1 What does "the ratio of purple blocks to red blocks is 3:5" mean?
Default: (1) Here is 3: 5, that is, in 8 squares, purple accounts for 3, red accounts for 5, a * * * accounts for 8, purple accounts for 83 and red accounts for 85. How many square meters of purple (eggplant) is the 83 of 984, and how many square meters of red (tomato) is the 85 of 984.
(2) Divide 984 square meters into 5 parts, 3 parts are eggplant and 5 parts are tomato. The total number of copies is 3+5 = 8,
Eggplant is 984÷8×3=369 (square meter), and tomato is 984÷8×5=6 15 (square meter).
2. Show the ideas and methods of solving problems in Example 2. ...
3. Show the problem-solving method of "practicing one and practicing three"
Summary: What have you gained from the life examples just now? What do you think is the key to the proportional distribution of application problems?
Default: (1) The key is to find out how many fractions of various quantities account for the total according to the known ratio, that is, to convert the ratio into component quantities and multiply it by how many fractions a number is. (2) According to the number of copies, first find the total number of copies, then each number of copies, and finally the number of copies.
Verb (abbreviation of verb) feedback detection
1. In this school sports meeting, 644 people signed up for various events, and the ratio of male to female athletes was 4 :3. Do you know how many female athletes take part in various events?
2. The junior teacher forms a triangle with a 40cm-long iron wire in the ratio of 4: 7: 9. Would you please help the junior teacher calculate the length of three sides?
3. There are 35 students in Class Six (1), 36 students in Class Six (2) and 34 students in Class Six (3). 2 10 colored flags need to be made at the entrance ceremony of the 12th track and field games. According to the proportion of the number of students in each class of grade six, how many colorful flags should be made in each class of grade six?
A standard basketball court is rectangular with a circumference of 86 meters. The aspect ratio is 28: 15. Find the area of this standard basketball court.
Sixth, the class summary
What did you learn from this lesson?
Seven. classwork
20 pages, 1, 2, 4, 5.
Blackboard design:
The method of solving problems by using proportional distribution
One is to know the quantity of distribution, and the other is to know the proportion of distribution.
Teaching analysis of ratio application in lesson plan 2;
Exercise in proportion.
Analysis of learning situation:
We have a preliminary understanding of the application of proportional distribution, and the solution to this kind of problem will be further consolidated through practice.
Teaching objectives:
Can use the meaning of ratio to solve the practical problem of distribution according to a certain ratio, further understand the meaning of ratio and improve the ability to solve problems.
Teaching strategies:
Practice, reflection and summary.
Teaching preparation:
Small blackboard
Teaching process:
First, basic exercises
(1) 1 The ratio of boys to girls is 3: 2.
1. The number of boys is the number of girls ()
2. The number of girls is () times that of boys, and the ratio of girls to boys is ().
3. The number of boys accounts for () of the class, and the ratio of the number of boys to the number of classes is ().
4. Class size is () of the number of boys, and the ratio of class size to the number of boys is ().
5. The number of girls in the class is (), and the ratio of the number of girls to the number of classes is ().
6. Class size is () of the number of girls, and the ratio of class size to the number of girls is ().
(2) The school bought 120 football and basketball, and the number ratio of football and basketball was 3 to 5. How many football and basketball did the school buy?
Divide 250 by 2 equals 3. What are the parts?
Second, variant exercises
1, the minuend is 36, and the ratio of subtraction to difference is 4 to 5. What is the subtraction? What is the difference?
2. There is a potion, which is prepared according to the ratio of potion to water 1 5000. 0.5 kg of this potion can be mixed with how many kilograms of this potion?
Teaching reflection:
Improve the flexibility and form of practice.
The application of Bibi teaching plan Part 3 Teaching content:
Beijing normal university printing plate sixth grade mathematics first volume page 55, page 56.
Teaching objectives:
1, the meaning of ratio can be used to solve the practical problem of distribution according to a certain proportion.
2. Further understand the significance of comparison and improve the ability to solve problems.
3. Cultivate interest in learning mathematics and develop good thinking quality.
Teaching focus:
Understand and master the significance of distribution according to a certain proportion and apply it in practice.
Teaching difficulties:
Lateral transfer's knowledge will be scored if the proportion is skillfully converted into the number of components.
Teaching preparation:
Multimedia courseware.
Teaching process:
First, review the traction (courseware demonstration)
Students, we have learned what "comparison" is through the study of the previous classes. So, if I tell you now that the ratio of boys to girls in a class is 5: 4, what information can you infer from this ratio? (Courseware presentation topic)
Students speak freely, the default is as follows
1, the class size is 9, including 5 boys and 4 girls.
2. The whole class "1", boys () girls () the whole class.
3. "1"For boys, girls are boys () and the whole class is boys ().
4. "1"For girls, boys are girls () and the whole class is girls ().
5. There are fewer girls than boys (or 20%).
6. There are more boys than girls (or 25%).
Follow-up: Can you also infer how many boys and girls there may be in this interest group? Ask three students to talk about it. Just make sure that the ratio of the total number of students is 5: 4. )
Second, introduce the situation and lead to the topic (courseware demonstration)
Yesterday, Mr. Wang and I bought a welfare lottery in partnership. I beat 30 yuan, and Mr Wang beat 50 yuan. As a result, we won the second prize with a prize of 8000 yuan. I want to split it 50/50, 4000 yuan each. Teacher Wang said it was unfair. what do you think? How to divide the bonus reasonably?
Third, explore and solve contradictions through cooperation.
1, can you help the teacher solve this problem? Please try it. We can exchange views and discuss ideas in groups.
2. Speak your mind. Sort out the feedback and show the students' problem-solving ideas one by one.
3. Is the bonus we got reasonable? How do we test it? (The sum of the two quantities should be equal to 8000, and the contribution ratio should be 3:5 or 5:3).
4. Summary: Allocating the 8,000 yuan lottery prize according to the amount invested is called proportional distribution. (blackboard writing: proportional distribution)
(Presentation Topic: Application of Comparison)
Fourth, independent exploration.
1. Courseware shows the textbook (1), and gives a basket of oranges to the big class and the small class, with 30 students in the big class and 20 students in the small class.
Thinking: How to divide this basket of oranges into big categories and small categories?
Students discuss the division method and come to the conclusion that it is more reasonable to divide according to the number of large classes and small classes.
2. The ratio of large class to small class is 3:2. After the students finish scoring, exchange points and fill in the form.
3. If there are 140 oranges, press 3: 2, how to divide them? Can you share it? Strive for a point.
Students have a try.
4. The way to communicate with classmates. Discuss doubts in groups and try to solve them in groups.
Fourth, the communication method, the teacher elaborated.
1, communicate in class and the teacher answers questions.
Three methods
(1), Method 1: Score with the help of the table.
(2) Method 2: Drawing.
The results showed that the total number of oranges was divided into five, three in the big class and two in the small class. First find out the number of servings, then multiply them by 3 and 2 respectively, and then find out the number of oranges in large and small categories.
140
140 ÷ (3+2) = 28 categories: 28×3=84 (pieces)
Small class: 28×2=56 people (each)
Q: Why is it "140 ÷ (3+2)"?
(3) Method 3: Solve the problem according to the meaning of the score. First, find out how many copies a * * * is divided into, then find out how many copies of' large class number' and' small class number' respectively account for the total number of oranges, and finally solve the problem according to the meaning of the score.
3+2 = 5 140×84 (piece)
140× = 56 (piece)
A: 84 large classes and 56 small classes are more reasonable.
2. Which of the above methods do you like best? Explain why. Guide students to summarize the ideas of method (3).
(1) Calculate the total number of allocated copies.
(2) Calculate the percentage of each part in the total.
⑶ Solve problems according to the meaning of fractional multiplication.
Verb (abbreviation of verb) consolidates practice and deepens understanding.
1, Xiaoqing needs to prepare 2200 grams of chocolate milk, and the mass ratio of chocolate to milk is 2: 9. How many grams of chocolate and milk do you need?
On the Arbor Day on March 12, the school assigned 602 and 603 classes the task of planting 60 seedlings, with 43 students in both classes. Think about it. If you were a brigade counselor, what percentage would you allocate and how many trees would you plant in each class?
3. Finish page 56 of the textbook and practice the third question: Reasonable breakfast.
Summary and evaluation of intransitive verbs
1, review the knowledge learned in this lesson and talk about the gains.
2. Assign homework.
Blackboard design:
Application of ratio
3+2 = 5 140×84 (piece)
140× = 56 (piece)
A: There are 84 large classes and 56 small classes.
The application of Bi teaching plan Part IV Teaching objectives
Make students further understand the characteristics and problem-solving ideas of proportional distribution of vitamins and application problems, and apply the knowledge of ratio to solve related application problems.
Further improve students' thinking ability such as analysis and reasoning and their ability to solve problems with specific knowledge.
Emphasis and difficulty in teaching
Apply the knowledge of ratio to solve related application problems.
Teaching preparation
Teaching process design
course content
Teacher-student activities
comment
First, review.
Second, the application exercises
Third,
Fourth, homework
1, let's talk about the specific meaning of each ratio.
The weight ratio of apples to pears is 2 ∶ 3;
The ratio of TV to radio is 5: 2:
The teacher-student ratio is 1∶25.
2. Oral answer
Exercise136; Tell me what you think.
Step 3 reveal the topic
1, exercise 137
Look for similarities and differences.
In these two questions, how many copies of each of the 40 trees corresponds to Billy?
Which of these two problems is proportional distribution and which is not? Why?
Think about the relationship between proportion and score. Will these two problems be solved?
Practice up and down;
What's the difference between these two questions? Why (1) use 40×3/5+3 and (2) use 40×3/5 to answer?
Step 2 practice in groups
(1) The number ratio of white rabbits to black rabbits in school feeding group is 5∶4. There are 15 white rabbits. How many black rabbits are there?
(2) The number ratio of white rabbits to black rabbits in school feeding group was 5∶4. Black rabbits have 12, and how many white rabbits have?
What are the similarities and differences?
Are these two questions the same as the proportional distribution problem? What is the difference?
3. Supplementary exercises
It shows that the ratio of boys to girls is 3: 4.
How many girls are there?
1) Students talk about the specific meaning of the above comparison.
2) orally supplement the application questions in proportion and answer them orally;
3) orally add a known quantity, find another quantity of application problems, and formulate orally.
Exercise 139
Feeling after class
Students can use the knowledge of ratio to solve related application problems.