Analysis of teaching material content:
This lesson is to let students understand the relationship between distance, time and speed in combination with specific situations. To this end, the textbook arranges a situation: who runs faster in two cars? Ask the students to sum up three quantities: distance, time and speed, and then speed = distance ÷ time. Combining the two questions, students can draw the following conclusions: distance = speed × time, time = distance ÷ speed, and further understand the relationship among distance, speed and time. Therefore, understanding the relationship between distance, time and speed is the focus of this lesson, and the difficulty is the unit of speed. After learning this lesson, students can solve some practical problems in life, arrange their time reasonably and improve their efficiency.
Analysis of learning situation:
For this lesson, the students have a certain understanding of speed. This lesson is mainly based on the actual situation, so that students can understand the relationship between speed and distance and time. For the fourth-grade students in our school, they have adapted well to cooperative learning and attach great importance to teachers' evaluation.
Teaching objectives:
Knowledge and ability:
Let students understand the concept of speed. Learn how to write speed.
Process and Method: Guide students to explore the quantitative relationship between speed × time = distance and apply it to solving problems.
Emotional attitudes and values:
Improve students' interest in learning, broaden their cognitive horizons, and let students feel the wide application of different means of transportation and human wisdom.
Teaching focus:
Understand the concept of speed and grasp the quantitative relationship between speed × time = distance.
Teaching difficulties: flexible use of quantitative relations to solve practical problems.
Course type: new course teaching methods: independent inquiry, cooperative communication, preparation of teaching AIDS: courseware.
Teaching process:
First, create situations and create problems.
What means of transportation did the students take? Do you know their speed?
Students speak freely.
Displays the speed of several vehicles:
The bus travels 30 kilometers per hour.
Motorcycles travel 20 kilometers per hour.
This car travels 60 kilometers per hour.
What does "speed" mean?
Students speak their minds.
Summary: "Speed" is used to indicate the distance traveled every minute and every hour.
(Design intention: Starting from students' existing knowledge, fully connect with students' real life, so that students can further experience that mathematics comes from life. )
Second, the learning objectives:
Grasp the quantitative relationship between speed × time = distance.
Third, the teaching process:
1, teach the concept of speed, learn how to write speed,
How to express speed in a simple way? The speed of the vehicle can be displayed in combination.
Students express their opinions.
Speed indication:
The speed of the bus is 30 kilometers per hour. Can be written as: 30 km/h
The speed of a motorcycle is 20 kilometers per hour. It can be written as: 20 km/h
The speed of the car is 60 kilometers per hour. Can be written as: 60 km/h
Ask students to use a unified symbol to express speed.
Teacher: Every hour and every minute refer to the unit time. The unit time can be every hour, every minute, every second, every day and so on.
Summary: In other words, the distance traveled by various vehicles per hour, minute and second is called speed.
2. When the speed of a car is 80km/h, can you calculate how many kilometers the car has driven?
Students express their opinions.
The speed of the bicycle is 225 meters per minute. I don't know the riding time, so I can't calculate the distance traveled.
Example 3:
(1) The car speed is 80km/h, how many kilometers is it feasible in 2 hours?
(2) Is it feasible for Teacher Li to ride at a speed of 225m/min and 10 min?
Ask a classmate to read Example 3.
How should this problem be solved? Please answer the questions independently and then exchange views with your deskmate. (teacher's patrol guidance. )
That classmate reported your solution to our classmate?
Student reports and exchanges come from
Your own solution.
80×2= 160
225× 10=2250
3. Summarize the relationship between speed, time and distance.
Teacher: In the above question, 80 km/h is (speed), 2 hours is (time), and the distance traveled is (distance). What is the relationship among speed, time and distance?
Students discuss in groups first, and then report the exchange.
Student: Guide the students to return to exchange and summarize:
Speed × time = distance
How should we seek time?
Xiaoming walked at a speed of 8 kilometers per hour and walked 24 kilometers. How many hours did Xiaoming walk?
Student: Answer independently and exchange returns, and come to the conclusion that distance/speed = time.
How to get the speed? (Change the speed of solving one of the problems)
A car traveled 540 kilometers in 6 hours. What's the speed of this car?
Student: Answer independently and exchange returns, and come to the conclusion that distance ÷ time = speed.
Teacher: The question about the relationship among speed, time and distance is called the trip problem. Today we are going to learn about travel.
(Design intention: The previous oral multiplication and pen multiplication are all about finding distance, so students are no strangers to finding distance. In teaching, students are fully allowed to study and explore independently, and sum up the relationship among speed, time and distance. Let students explore the relationship between distance-speed = time and distance-time = speed by knowledge transfer. )
Fourth, ask questions in class.
Show several speeds and write them in a simple way.
1, (1) cheetahs can run at the speed of 1 10 km per hour and can write-
(2) The speed of a butterfly is 500 meters per minute, and writing-
(3) The speed of sound propagation is 340 meters per second. characters
When the students calculate independently and correctly, let the students talk about how to do it. Increase the practice of judging speed appropriately.
Do it on page 53 of the textbook.
Design intention: pay attention to hierarchy through design, so that students can consolidate and improve their knowledge. )
Verb (abbreviation of verb) summary.
What have you learned through today's study? What did you get?
[Design Intention]: Guiding students to review and organize what they have learned is helpful to cultivate students' collective thinking. Students' self-evaluation and mutual evaluation not only pay attention to what students have learned, but also pay attention to whether students actively participate in the learning of mathematics activities and their interest in learning mathematics.
Blackboard design:
The relationship between speed, time and distance
80× 2 =160km 24÷8=3 hours.
540÷6=90 (km/h)
225×10 = 2250m
Speed × time = distance
Distance/speed = time
Distance/time = speed