Let's talk about textbooks first.
1, teaching material analysis.
This unit mainly permeates some ideas and methods about tree planting. Through some common practical problems in real life, students can find some laws, extract their mathematical models, and then use the found laws to solve some simple practical problems in life.
The thinking method to solve the problem of planting trees is a mathematical thinking method widely used in real life. The problem of planting trees usually refers to planting trees along a certain route. The total length of this route is divided into several sections (intervals) on average. Due to different routes and different tree planting requirements, the relationship between the number of road sections (intervals) divided by routes and the number of trees planted is also different. In real life, there are many similar problems, such as installing street lamps on both sides of the expressway, arranging flowers in flower beds and queuing squares. There is a problem of the relationship between the total number and the interval number, so we call this kind of problem the problem of planting trees.
In the problem of planting trees, the route of "planting trees" can be a line segment or a closed curve, such as square, rectangle and circle. Even regarding the planting of a line segment, there can be different situations such as planting at both ends, planting only at one end of the country, and not planting at both ends. Through some examples in life, this unit allows students to sum up laws according to different situations and use these laws to solve similar practical problems.
Example 1 is to discuss the problem of planting trees on a line segment, and both ends should be planted. Example 2 is to discuss the situation of not planting trees at both ends. According to the editor's intention, let students go through the process of mathematical exploration such as guessing, experiment and reasoning, solve complex problems from simple situations, let students choose their favorite methods to explore the relationship between the number of trees planted and the number of intervals, inspire students to discover the law through phenomena, and let students initially understand the thinking method of solving tree planting problems and its application in solving practical problems.
2. Teaching content: Example 1, Example 2 and the corresponding "doing one thing" and the exercises in Unit 8, Volume 2, Grade 4, Primary School Mathematics, published by People's Education Press.
3. Teaching emphases and difficulties:
Focus: Guide students to explore and summarize the relationship of "tree = interval number+1" from practical problems.
Difficulties: assimilate similar problems in real life into "tree planting problems" and solve these practical problems with the thinking method of tree planting problems.
3. Class arrangement: This class is the first class.
Second, say the goal.
Knowledge and skills:
1. Experience the process of exploring simple laws in interval arrangement and simple mathematical laws in similar phenomena in daily life, have a preliminary understanding of simple laws, and apply this understanding to solving simple practical problems, and feel the extensive connection between mathematics and life.
2. Through observing, guessing, operating, verifying and communicating with others, cultivate students' awareness and ability to observe things around them from a mathematical perspective and analyze various phenomena in daily life from a mathematical point of view.
Process and method:
Explore the law by observing, guessing, operating, verifying and communicating with others.
Emotional attitudes and values:
Through practical activities, cultivate students' ability to apply what they have learned to solve practical problems, understand the close relationship between mathematics and phenomenal life, and form the habit of thrift and reasonable arrangement of expenses from an early age.
Third, talk about learning.
Before learning these contents, students have initially accumulated some experience in exploring laws. Because this law is very common in daily life, it is easy for students to find relevant prototypes in their lives, so they are more likely to experience the fun and success of exploring the law.
Fourth, the teaching method of speaking.
Verb (abbreviation for verb) talks about teaching procedure.
On teaching process: I divide this class into four processes to promote teaching.
First, situational introduction
"There are many mathematical problems hidden in the' tree planting activities' used to change and purify our living environment. Who found it? "
Design intention: It is necessary to stimulate students' interest in learning and make them feel that math problems originally come from life practice.
Second, explore new knowledge.
1. Show an example 1.
(1) Read the topic by name and understand the meaning of the topic.
(2) Think independently: Will you solve this problem?
Design intention: cause cognitive conflict and inspire students to seek feasible methods to verify their mathematical conjecture.
2. Draw a line diagram by hand, understand the meaning of the problem through the line diagram, find the law and solve the problem.
Design intention: Infiltrate common methods to solve problems to students.
⑵ Students report and make a preliminary model. Most students realize the relationship between the number of trees and the number of intervals in this link, but teachers should not rush to achieve success, and let students understand that any scientific conclusion should be based on universality.
3. Students solve the road length and tree spacing by themselves, compare the relationship between the spacing and the number of trees, and then summarize the relationship between them. Create a natural state for all students.
4. Re-check the different solutions of the example 1.
Design intention: Let the students solve their own cognitive contradiction with the explored laws. This contradiction will be naturally resolved here, and all the students will be suddenly enlightened.
Third, consolidate the practice.
Fourth, class summary.
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