1. Make students experience the process of data collection, collation, description and analysis, further understand the role of statistics in real life, and understand the close relationship between mathematics and life.

2. Let the students know and draw the vertical composite bar chart, ask and answer simple questions according to the chart, find mathematical information and make simple data analysis.

3. Experience the whole process of statistics in the process of independent inquiry, cooperation and exchange, and cultivate practical ability and participation consciousness.

Emphasis and difficulty in teaching

Teaching emphasis: can complete the corresponding vertical composite bar chart according to the provided data.

Teaching difficulties: being able to find information, analyze information and ask simple questions according to the vertical composite bar chart.

teaching process

First, look at a single bar chart.

1, Teacher: Yesterday, the teacher arranged for students to collect and sort out the number of boys and girls in grades one to six. Who can tell me how you investigated?

Student 1: Ask teachers of all grades.

Student 2: Ask your former classmates.

2. Teacher: It seems that students know how to use the resources around them, which is good. Which student would like to share your findings with you? Born to perform on the stage.

Teacher: How do you describe the data?

Health 1: I used a simple statistical table and a simple histogram.

Health 2: I use double-entry statistics.

Teacher: Is it the same as everyone's survey?

Health 3: Same.

Teacher: You are really diligent and know how to apply what you have learned!

3. Teacher: The teacher also collected data and made a composite statistical table.

Statistics on the number of students of all grades in the fifth primary school (courseware shows composite statistics)

Gender Grade One, Grade Two, Grade Three, Grade Four, Grade Five and Grade Six

schoolchild

girl student

Teacher: (referring to courseware) Is there a more vivid and intuitive way to describe these data besides statistics? Health: bar chart.

Teacher: So many students want to go together. How can we draw a bar chart? Please think it over. When drawing a bar chart, draw it first (horizontal axis), then (vertical axis), and then draw a straight bar to represent the data. Pay attention to writing the name of the chart.

Teacher: OK, now, please take out the exercise cards arranged by the teacher before class, take them well and listen to the requirements: work together at the same table to see who can draw quickly and accurately.

Hands-on operators patrol.

Step 4 make comments

Students went on stage to show their works.

(Up and down the statistical chart of the number of boys and girls in grade four)

Teacher: OK, let's stop our pens (pause for a moment and look around the classroom). Let's take a look at the statistics obtained by this group of students first. This is a statistical chart of the number of boys (the teacher points to the title). Who will comment on this painting? Okay, where is it?

Student: The intervals between grades are equal; The width of each straight rod is the same; Marked data; And write the name of the statistical chart. Teacher: Are you satisfied with his evaluation?

Teacher: The comments are in place, just like a little teacher. Let's take a look at another student's statistics on the number of girls. Is the batter out? Teacher: Yes, it's done.

Teacher: The teacher also drew two simple bar charts based on the collected data. Please look at the big screen.

(The courseware shows two simple bar graphs.)

Teacher: Look at these two bar charts carefully. Are there more boys or girls in the fourth grade?

Teacher: How do you know? Where did you see it? What else can I see?

Health: The data in the column. The length of the bar.

Teacher: Oh, first look at the data of boys above, and then look at the data of girls below.

Look at the straight line of the boy above, and then look at the straight line of the girl below.

Teacher: What about the third grade? What about the fifth grade? What about the sixth grade?

Second, the teaching composite bar chart

1, for a composite bar chart.

Teacher: The teacher found that to compare the number of boys and girls in a grade, we should first look at the number of boys above and then look at the number of girls below. Always like this. Take a look and see what you think.

Health: It's very troublesome.

Teacher: Well, the teacher feels the same way. Who can design a more convenient comparison scheme?

Health: You can combine two simple bar charts.

Teacher: It is to combine two simple bar charts into a statistical chart.

Teacher: When the teacher was patrolling just now, I found a classmate drawing a composite bar graph. Would you like to show your work? (Projection shows composite bar chart)

Teacher: What do the students think of his method?

Health: OK.

Teacher: It seems that the students all agree with your group's painting method. Please tell me what you think.

Health: It is more convenient. The students answered.

Teacher: What kind of statistical charts can be combined?

It seems a little difficult to express. The teacher reminds you (back to the courseware) to observe these two statistical charts. What are the similarities?

Student: Their horizontal axes all indicate grades, and their vertical axes all indicate the number of people.

Teacher: So it can be displayed in a statistical chart. You got it? Who said that again?

Teacher: What's inconvenient when comparing the number of boys and girls in each grade just now?

Student: The straight line distance between boys and girls is a bit far.

Teacher: Yes, so that we can draw two straight lines side by side like him.

Teacher: How do you know which bar represents boys and which bar represents girls?

Health: Distinguish by color.

Teacher: Oh, by color? Can you say that again?

Student: Green stands for boys and red stands for girls.

Teacher: Is there any other way to tell the difference?

Health: Use different stripes to distinguish them. (Shadows and Blanks)

Teacher: Only we know what different colors represent. Can other people who look at pictures understand?

Teacher: In order to distinguish it more clearly, we can use legends to show it. Usually, we will mark the legend in the upper right corner of the statistical chart and explain it with numbers and words.

Teacher: What's the name of a statistical chart made by counting two or more quantities like this? Composite bar chart? . (blackboard writing: double bar chart)

2. Draw a composite bar chart.

Teacher: Who can tell us what we should pay attention to when drawing composite bar charts?

(Courseware demonstration: indicate the name, indicate the legend, with equal intervals and the same width, and coordinate the straight lines to represent the data. ) Teacher: Can you draw a double bar chart now? Please continue to improve the statistical chart just now and draw it into a composite bar statistical chart.

Show works, students evaluate. (Show 3 works)

Teacher: Please comment on his works in one sentence.

Teacher: It seems that the students have mastered the drawing method of composite bar chart statistics! The teacher also asked the computer doctor to draw a new statistical map. Please look at the big screen.

3. Similarities and differences between composite bar chart and single bar chart.

Teacher: Let's make a comparison. What are the similarities and differences between double bar charts and single bar charts? You can communicate with your deskmate.

Similarity: Numbers are expressed by bar length;

Difference: single bar chart only shows the change of one quantity, while double bar chart can show the change of several kinds of data at the same time; A single bar chart has no legend, and a double bar chart should be marked with legend.

Teacher: Yes, when we count two or more numbers, we can make a composite bar chart, which is more intuitive and convenient for comparison.

(blackboard writing: intuitive image, easy to compare) This is the advantage of composite bar chart.

Teacher: Please answer the following questions according to the statistical chart:

(Student answers) Question:

1. Which grade has the most boys? Which grade has the fewest boys?

2. Which grade has the most girls? Which grade has the fewest girls?

3. Which grade has the most boys and girls? Which grade has the least number of boys and girls?

4. What other information can you get?

Third, consolidate and deepen, apply what you have learned.

Teacher: Actually, we have a lot of knowledge about statistics in our life. Let's apply what we have learned today to solve several practical problems.

1, how do you let others know which one in your statistical chart represents the population of the city and which one represents the population of the countryside?

The following is a statistical map of urban and rural population in a certain area.

Are the two belts representing urban filling and rural areas drawn separately or next to each other?

What year is the largest population in the city? Which year is the least?

Which year has the largest rural population? Which year is the least?

Which year has the largest population in urban and rural areas? Which year is the least?

What else can you get?

2. The sales of two brands of juice drinks in a supermarket in 1 month, February and March are as follows. Complete the following statistical chart.

(1) What information can you get from the statistical chart?

(2) If you are the manager of a supermarket, how will you purchase goods next month? Why?

(3) If you are the director of a certain beverage and see this statistical chart, what measures will you take?

How do you let others know which one represents the population of the city and which one represents the population of the countryside on your statistical map?

3, the fourth grade extracurricular group number statistics

Draw a bar chart according to the information in the above table.

Fourth, comb the knowledge and understand the role.

Teacher: Students, what have you gained from this class? Can you say something?

Teacher: You have gained a lot!

In this lesson, we have gone through the whole statistical process from collecting and sorting out data, to creating composite bar charts to describe and analyze data, and finally to solving problems. After class, organize your harvest into math diary, and we will talk about it next class.

Blackboard design: the composite bar graph is intuitive and easy to compare.