Teaching content: experimental textbook of compulsory education curriculum standard People's Education Publishing House, Unit 7, Volume 2, Grade 4 Examples: 108~ 109, 1. Knowledge background: The course of "Broken-line Statistical Chart" is to know a new statistical chart-simple broken-line statistical chart on the basis that students master the basic methods of collecting, sorting, describing and analyzing data and can express statistical results with statistical tables and histograms. In addition to expressing quantity, the single broken line statistical chart is mainly used to express the increase or decrease of a quantity. At the same time, actively read the single-line statistical chart, laying a good foundation for the study of the composite statistical chart.

Teaching objectives:

1. Understand the broken-line statistical chart and its characteristics on the basis of the bar statistical chart.

2. Be able to analyze data and solve problems according to the broken-line statistical chart description, and further understand the close relationship between mathematics and life.

3. According to the change of data in the line chart, predict the result or trend of the problem and realize the function of the line chart.

Teaching emphasis: understand the broken line statistical chart and its characteristics.

Reflection on teaching design: There are many similarities between broken line statistics and bar statistics. How to guide students to transfer and apply the knowledge of strip statistics when learning broken line statistics is the most concerned aspect of this teaching design. Therefore, when designing the new curriculum, a histogram is presented, which is intended to let students review and consolidate the relevant knowledge of the histogram, and ask questions: () The number of visitors has increased fastest from ()? Can you find a way to see that the number of people increased the fastest from 2007 to 2008 (the growth point of old and new knowledge) without calculation? In the teaching of new knowledge, two cognitive links are designed: one is preliminary perception, which allows students to analyze the similarities between the two statistical charts, that is, they can all see the numbers. Secondly, after in-depth exploration and comparison, we can find the difference between the two statistical charts, that is, the broken-line statistical chart can clearly show the change of a quantity. In order to better understand the characteristics of broken-line statistical charts, different levels of exercises are designed in the exercise to further strengthen the characteristics of the two statistical charts. At the same time, in the teaching of this course, we should also pay attention to the cultivation of students' environmental awareness and scientific spirit.

Teaching process:

First, create a situation

1. courseware shows pictures of global climate change and ecological environment deterioration. How do you feel when you see these pictures? (Students speak freely. )

Teacher: Learn relevant scientific knowledge, start from the small things around you and protect the earth with your own practical actions. Have you visited the science and technology exhibition? By visiting the science and technology exhibition, you can learn a lot of knowledge outside the textbook. The following is a statistical table of the number of students visiting the Science and Technology Museum in a city from 2003 to 2009. Look carefully, what information can you learn from the statistics?

Statistics on the number of students visiting science and technology museum in a city

Guide students to observe statistical data, get information and talk at the same table. )

2. Question: Which two neighbors are the fastest growing visitors? How did you know? (Students often use calculation methods. )

Can you find a better way to see that the number of visitors increased the fastest from 2007 to 2008 without calculation? After discussion, the students think that a bar graph can be made. )

4. Teachers show the following statistics in turn:

Let the students observe independently and feel initially. Think about your findings in two statistical charts. Prepare for the following exploration.

Second, explore new knowledge.

1. Comparison: What are the similarities between the bar chart and the new (II) chart? Students should think independently before communicating in class. )

(1) Both statistical charts have a horizontal axis and a vertical axis. Emphasize what the horizontal axis represents and what the vertical axis represents.

(2) Both statistical charts can show the number of visitors each year.

2. Dig deeper: What's the difference between the bar chart and the second chart?

(1) Discuss in groups of four, and then communicate with the whole class.

Thinking 1: What is the number of visits per year represented by the second statistical chart? Can you tell which year has the largest number of tourists? Which year has the fewest tourists? (Quantity is indicated by "dots". )

Thinking 2: How did the number of visitors change in the next two years? What do you think of the increase, decrease or unchanged number of visitors? (see the change of quantity through the inclination of the line segment. )

Thinking 3: In which year did the number of tourists increase the fastest? Can you tell at a glance now? (See the magnitude of quantitative change through the inclination of the line segment. )

Blackboard Writing: Flat-Constant Fluctuation-Change

(2) Students use gestures to indicate the change and invariability, increase and decrease, and the range of change.

(3) With the help of this statistical chart, we can understand the overall changes in the number of tourists from 2003 to 2009. The courseware demonstrates the whole rising process. Let the students observe the whole broken line and feel the overall changing trend.

3. Teacher's summary: This kind of statistical chart is characterized by reflecting numbers through "points" and reflecting the increase and decrease of numbers through the ups and downs of broken lines.

Do you know the name of this statistical chart? (Title on the blackboard: statistical chart of broken lines)

5. Forecast: According to the data of this statistical graph, how many people will visit 20 10? What is the basis of your prediction?

Summary: Predicting the number of people is only a "possibility". If you want to know how many people will visit, you must talk through surveys.

Third, practical application.

1. statistical chart analysis of broken lines: Exercise 19, Question 6, on page 1 15 of the textbook (omitted).

Look at the chart and answer the questions. Tell me what good suggestions you have.

2. Comparison of precipitation in Kunming in May 5- 10/October, 2009.

According to the data in the above table, make a statistical chart of broken lines (with courseware) and present it to students.

(1) What does the chart show?

(2) What other questions do you want to ask?

3. Mingming investigated the use of plastic bags in five children's homes for a week and drew a statistical map.

Statistics on the number of plastic bags used by five families in a week

First, show me the statistical chart of the dotted line below.

Carefully observe and analyze the broken line statistical chart and talk about your own ideas. (Students discuss in groups of four. )

(1) Ask students to describe different things and make bar charts; It is convenient to describe the change and development trend of the same thing and make a broken line statistical chart.

(2) Make a bar chart (drawn according to the same content).

(3) Teacher's summary: Under what circumstances, when drawing a broken line statistical chart and a bar statistical chart, we should make a reasonable choice according to the actual needs of the statistical content.

4. Reflection (what can we do): The climate is changing rapidly and the environment is getting worse. It's time for people to reflect on their behavior. As ordinary people, we can pursue a low-carbon life, save water, electricity and contracts, put an end to waste, and start from the small things around us.

Fourth, expand: develop courseware introduction (demonstration) statistics.

In China, the concept of statistics has existed since ancient times, but it developed rapidly in the Southern Song Dynasty. Historian Zheng Qiao's atlas thought is similar to the drawing principle of modern statistical maps. Nowadays, statistical charts have been widely used in various fields, and have evolved into various statistical charts such as column charts, pie charts, area charts and radar charts.

Teacher's summary: What did you gain and feel from this class? (Teachers and students can be organized to summarize according to the actual class situation. )

Author unit

Kunming Panlong District Tong Ming Primary School

Editor: Li Ruilong.