Main contents of teaching: Understand and master the quantitative relationship between distance, time and speed, and solve simple problems in life according to the relationship between distance, time and speed.

Characteristics of textbook compilation: This course is arranged in the second section of Unit 5 Division, which is based on learning the related knowledge of division and being exposed to problems related to distance, time and speed. By studying this part, students can understand the common quantitative relations, and at the same time, they can further understand the relationship between division and multiplication. This part of the content textbook requires students to know what kind of quantity can be called speed, but they don't need to know the definition of speed and its significance and value in real life. So the textbook first arranges the question situation of which object moves faster. By comparison, students know that the speed of an object's movement is related to distance and time, so they can get the distance, time and speed. At the same time, in the process of comparison, we also pay attention to the diversity of algorithms.

The core idea of mathematics in textbooks is to understand the practical significance of distance, time and speed and the diversification of algorithms.

learning target

1. Students understand and master the relationship between distance, time and speed, and understand the practical significance of each quantity.

2. Students can solve practical problems in life according to the relationship between distance, time and speed in the process of learning the relationship between them.

3. Enhance students' awareness of using various strategies to solve problems and their ability to collect and process information.

Focus: Understand and master the relationship between distance, time and speed.

Difficulty: Understand the actual meaning of each quantity.

Teaching aid preparation: slide presentation courseware

Teaching process:

Creating situations, understanding relationships and solving problems are diversified.

1, hiking meeting.

Dalian is a beautiful coastal city. Do you know that Dalian is also an international hiking city? Last Saturday and Sunday was the 5th International Walking Conference held in Dalian. Naughty and Xiaoxiao also attended the hiking meeting. Let's see what they are talking about.

Show pictures:

Q: Who walks faster, naughty or smiling?

1) first estimate who walks fast.

2) Teacher: Is there any good way for you to know exactly who walks faster? Write down your ideas in this book and see whose method is better.

3) Teachers' patrol guidance. The situation with correct estimation will appear as follows.

Let's see who is faster.

140÷2=70 (m/min), 300÷5=60 (m/min), because 70 > 60, naughty walks faster.

Let's see who has walked a long distance in the same time.

140÷2=70 (m/min), 70×5=350 (m), because 350 > 300, naughty walks faster.

300÷5=60 (m/min), 60×2= 120 (m), because 120 < 150, naughty people walk faster.

C, see who walked a long distance in the same time (all walked 10).

140×5=700 (meters), 300×2=600 (meters), because 700 > 600, naughty walks faster.

4) Group communication (talk about your own ideas, be clear about what you are comparing, and pay attention to listening to other people's ideas and opinions)

5) Exchange reports of large groups. Find the name, such as 140m, 300m. What are the names of 2 and 5? (blackboard writing: travel time) Q: 140 \

Introduce speed and unit: because the distance unit is meters and the time unit is minutes, the speed unit is meters/minutes. What conditions do I have to know to get speed? (blackboard formula)

3. Q: Look at these two quantitative relationships. What's the connection between them? Then can you tell me how to find time according to this connection? (blackboard formula)

4. Summary: Just now we learned the knowledge of travel time and speed (blackboard topic) and knew the relationship between them. Below, we will solve several practical problems according to these relationships.

5. Exercise: [Students' answers should be clear about the basis for solving problems]

1) The 5th International Walking Conference in Dalian, the longest route is about 30 kilometers. It only takes five hours for the first batch of people to walk the whole distance. What is their walking speed?

2) Who goes to the Children's Palace first? (seeking time)

3) How many kilometers is the distance from A to B?

Observe what 70×4=280 means. What is 280÷4 seeking? Equal to what? What does 280÷70 require? Equal to what?

Exercise: Write the numbers of the following two formulas directly according to the first formula.

50×4=200 30×70=2 100

200÷4= 2 100÷30=

200÷5= 2 100÷70=

Seeing the relationship between factor and product, which quantitative relationship do you think we only need to remember among the three relationships of distance, time and speed? ("Speed times time equals distance")

Understand the practical significance of speed.

1, Teacher: Through the study just now, we know how to judge the speed of an object. Speed is a good data, so what knowledge about speed have you learned in your life? (living example)

2. Show the following two pictures.

Q: We know that lightning happens at the same time. After reading these two sets of data, can you tell us why lightning is always seen first?

Then you will hear thunder?

It seems that mathematics can also help us to explain the phenomena in our daily life.

3. Show the following three pictures.

The speed at which the plane takes off is about () km/h. The maximum speed of a car on the highway.

Do not exceed () km/h.

4. violate the rules on the expressway.

1) Teacher: On May 25th, 2007, the teacher saw such a report in the newspaper. [Show headlines of news reports]

BMW became the speed racing car of "Crazy Horse Song and Dance Show".

2) Do you want to know what's going on? [Presenting news report]

"Two days ago, the Oriental Morning Post reported that a mobile electronic speedometer of the Third Brigade of the Traffic Police of Huzhou Expressway captured the 1 BMW speeding car on the Zhejiang-Anhui Expressway, and the speed showed 186 km/h, but the traffic police thought that the speed of this BMW car was far more than the1shown by the electronic speedometer on the section from Si 'an to Nanxun in Changxing County. "Please calculate the speed of this car in kilometers per hour according to the data given in the figure.

Guide picture: What mathematical information do you see from the picture? Speaking of time, Q: What can we learn from these two time records? )

Students try to calculate the speed.

Ac computing process.

Students, do you know that in 2006, the number of traffic accident deaths caused by speeding reached more than 20 thousand. What shocking data! Only by obeying the law can life be better! However, there is an object that is so fast that the traffic police can't control it. The speed of Shenzhou 5 spacecraft reached 8 km/s, which is (28,800) km/h. ..

Solve practical problems.

Go to Shenyang on business. Xiao Min's father will drive from Dalian to Shenyang. The following are some data and photos collected by Xiao Min from her father's trip. What math questions would you ask?

1, the speed from Xiao Min's home to the expressway entrance is 800 m/min.

2. The speed of expressway is about110 km/h. ..

3. It takes 10 to drive from Xiao Min's home to the high-speed entrance.

4. The total length of Shenyang-Dalian Expressway is about 330 kilometers.

Xiao Min's father saw the following sign at Laohutun toll station.

What did you gain from this class?