Teaching clips:
Teaching route:
1, transition: The wool in the teacher's hand is really naughty. Look, they jumped on the big screen. (The teacher shows the courseware 1 and shows a line segment.) Please observe carefully. What do you find? A straight line segment has two endpoints. )
If you are given a ruler, can you measure the length of this line?
3. How do you measure it? After the students say it, let the students draw a 5 cm long line segment and let the deskmates check each other for correctness.
4. Who can fully talk about the characteristics of line segments? (Student answers)
(B) linear teaching
……
(3) Teaching ray
1. Please imagine again. What kind of line can you get if one end of a line segment is infinitely extended? (thunder, straight, with an end point, can't measure the length. )
2. What light do you see in our life? The courseware shows the flashlight and the light of the sun.
Students answer with life.
There are many lights in life. I find that most of it is light, which makes our life colorful. Now, please draw some rays in your exercise book. Think while painting. How many can you draw? (Show courseware)
Student report summary: A little bit can draw countless rays. )
Step 4 show a set of exercises
Please compare the similarities and differences of line segments, straight lines and rays in groups, and complete the table on the big screen. (Show courseware)
(1) Do it yourself.
(2) Group discussion
(3) Students report their grades.
……
Reflection: On acquiring knowledge, Suhomlinski has a classic exposition: teaching students to acquire knowledge with the help of existing knowledge is the highest teaching skill.
The teaching in this section pays attention to "student-oriented", fully arouses students' initiative, implements teaching along students' learning ideas and needs, and urges students to actively observe, think, explore independently, cooperate and communicate in groups, and become discoverers, researchers and explorers of knowledge. At the same time, teachers pay attention to the relationship between mathematics and life. The specific performance is as follows:
1, make full use of visual teaching AIDS to show demonstrations and operate feelings, and help students establish appearances and develop spatial concepts. Demonstrated by computer, both ends of a line segment extend infinitely into a straight line, and one end extends into a ray. This demonstration fully shows the relationship between the three lines and is vivid. More convincing than the teacher's empty and abstract language.
2. Give students the space and time to think, explore and feel the process of knowledge formation and development independently. For example, when distinguishing the relationship between straight lines, line segments and rays, let the students discuss it by themselves.
3. In teaching, if you draw a straight line after one o'clock, a straight line after two o'clock and a ray after one o'clock, how many straight lines can students draw? The operation of the problem. A concept that allows students to explore independently and construct actively.
In a word, this course conforms to the law of students' thinking development, provides a learning background suitable for students to build knowledge, and adopts various learning methods. Students have experienced the process of knowledge formation and development, developed the concept of space and gained a profound experience of "doing mathematics".