Teaching objectives
1. Further deepen the understanding of the importance of statistical work.
2. Further deepen the understanding of the quantitative relationship of the average problem and master the problem-solving methods skillfully.
3. Learn to analyze the contents contained in the statistical table and the relationship between the parts, and further master the preparation and inspection methods of a statistical table.
Teaching focus
This lesson combs and reviews three contents: average, statistical table and statistical chart. By learning and mastering the quantitative relationship of the average, the key to solving problems and methods, we can further clarify the content and quantitative relationship of statistical tables and master the methods of compiling, filling in and checking statistical tables.
Teaching difficulties
Comprehensively use the knowledge learned, analyze and answer the application questions about average value, and compile and check statistical tables.
Teaching step
First, pave the way for pregnancy. Demonstration courseware "Simple Statistics"
1, teacher's question introduction.
Students, memory is the mother of wisdom. Which of you has the best memory? Ask a question to test everyone: What statistical knowledge did you learn in primary school? Which book did you study?
2. Student report.
In Unit 1 of Book 10, I learned to collect and sort out data and find the average value.
In Unit 4 of Volume 12, I learned statistical tables and charts.
Second, summarize and sort out.
(1) Deepen the understanding of the importance of statistical work.
1. Students discuss and report.
2. Teacher's explanation: Statistical knowledge is widely used in production, work and scientific research. We should learn statistical knowledge well and improve our statistical ability.
(b) Review the average. Continue to demonstrate the courseware "Simple Statistics".
Example 1. The number of students in seven classes in a junior high school is as follows:
Grade one of junior high school: 40 students in Class One and 38 students in Class Two;
Grade two: 40 students in Class One and 40 students in Class Two;
Grade three: class one has 4 1 person, class two has 38 people and class three has 36 people.
1. Students read the questions and analyze the conditions and questions.
2. Answer independently.
3. The teacher asked: What must be found first to find the average value of a set of data?
What is the average value of 1?
If the average number of seven classes is known, how to calculate the total number of these seven classes?
4. Inspiring thinking: What is the key to finding the average?
The key: first find out the total number of a group of numbers, and then know how many copies to divide on average. Dividing the total by the total to be divided is equal to the average.
5. practice.
Sampling five times in a pile of wheat, the 1000-grain weight of wheat is 32g, 34g, 36g, 35g and 38g respectively. What is the average 1000-grain weight of wheat measured these five times?
6. Student independent solution Example 2.
The sixth grade students of Zhenhua Primary School make teddy bears. There are 48 students in Class One, and 267 students make toys. Class two, 50 people, * * * do 292; There are 47 people in Class Three, each with six. How many do sixth graders do on average?
7. Thinking: Can you try to sum up a relationship by combining the solving process of two examples?
Total quantity/total number of copies = average value
(3) sorting out and reviewing statistical tables.
1, guide.
2. Teacher's question: How many columns are there horizontally and vertically in the statistical table? What do they mean?
Make a statistical table. What does it generally include?
3. Analyze the relationship between the data in the statistical table, and fill the vacant data according to the filled data.
4. Teacher's explanation: The content of the statistical table is determined according to the actual needs of statistics. When compiling and analyzing statistical tables, the key is to make clear the relationship between each column and quantity.
5. practice.
(1) The following records are the results of the sit-up test for girls in a class 1 minute (unit: times).
25 33 3 1 28 13 36 30 29 32 2 1
32 29 25 30 19 27 3 1 35 26 28
Fill in the following table according to the above results, and then calculate the average number of exams for girls in this class.
Number of people taking the test: total times: average times:
(2) The following is the statistics of physical education scores of students in two classes of Grade 6 in Yuxin Primary School last semester.
① According to the data in the above table, answer the following questions:
② How many people are there in each of the two classes? (Keep one decimal place before the percent sign)
(four) the collation and review of statistical charts.
1, guide.
The following two statistical charts reflect the first and second electronic instrument factories in a city. Please look at the picture and answer the following questions.
(1) As can be seen from the statistical chart of dotted line, which factory's output value is growing rapidly?
(2) As can be seen from the histogram, which factory has more workers? Which factory has more technicians?
(3) Which factory do you think produces well? Why?
2. Compare and continue to demonstrate the courseware "Simple Statistics"
3. practice. The following is a statistical table of art scores of a class in one semester.
Make a histogram according to the data in the table.
Third, the class summarizes.
What did we sort out and review in this class? What is the key to solving the average problem and compiling statistical charts?
Fourth, practice in class.
1, the key and method to solve the average problem in spoken English.
2. Dictate the contents of statistical tables and test the methods of statistical tables.
3. The characteristics and functions of oral statistical charts.
Verb (abbreviation for verb) assigns homework.
1, the distance from port A to port B is140km. It takes 4.5 hours for a ship to sail from Port A to Port B, but it takes 1 hour to return because it is not only countercurrent. Find the average speed of the ship.
The average weight of Li Xiaochun, Wang Fang and Zhang Qiang is 43kg. Among them, Li Xiaochun weighs 44 kilograms and Wang Fang weighs 40 kilograms. What is Zhang Qiang's weight?
3. Prepare a statistical table according to the following statistical chart.
The monthly precipitation in a certain place last year is as follows.
According to the data in the above table, make a broken line statistical chart.
Sixth, blackboard design