Teaching objectives:
(1) Through practical activities, let students understand the meaning of "one number is several times that of another number" and realize the relationship between quantities.
(2) Make students experience the process of transforming the practical problem "how many times is one number" into the mathematical problem "how many other numbers are included in one number", and initially learn how to solve simple practical problems by transformation.
(3) Cultivate students' cooperative consciousness and improve their inquiry ability.
Teaching focus:
Make students experience the process of abstracting the quantitative relationship of "one number is several times of another number" from practical problems, and solve practical problems with multiplication formula and quotient skills.
Teaching difficulties:
Using analytical reasoning, the quantitative relationship of "how many times is one number another" is transformed into "the division meaning of several other numbers in one number."
Preparation of teaching AIDS: courseware, sticks, etc.
Teaching process:
(1) review
1. There are three dancers in Class Two, Grade Two, and the students who learn painting are twice as good as those who learn dancing. How many students are studying painting?
A. take the students to answer and talk about the thinking process;
B: Please ask six painting students to wave to everyone and report their academic achievements. The teacher congratulated the students who got excellent grades.
2. There are 6 students in Class 2 of Senior Two who learn to sing, while those who learn to play table tennis are three times as good as those who learn to sing. How many students learn to play table tennis?
3. There are four students in Class Two, Grade Two who learn to play the piano, four times as much as those who learn to play the trumpet, and how many students learn to play the trumpet?
(2) Hands-on operation to explore new knowledge.
1. Show the theme map of Example 2 on 54 pages (animation courseware)
Teacher: Do you want to take part in this game?
2. Activity: Students build planes by themselves; (Playing music)
Report the results
Teacher: According to your plane, who can ask a question for everyone to guess?
It leads to "finding the division meaning of several other numbers in a number"
4. The courseware shows Xiao Qiang's question in the example: "I flew three planes and used several times as many sticks as Xiaohong."
5. Panel discussion
6. Reporting the results, the students found the idea of "how many times a number is another number" in their thinking and full exploration, that is, "how many times a number is another number" means "how many other numbers does a number contain" and calculated by division.
15÷5=3
(C) the use of knowledge to solve problems
1. The courseware gives the situation diagram of Example 3.
2. Students put forward the problem of division calculation according to the pictures;
3. According to the questions raised, discuss the solutions in groups;
4. Students' independent column solution;
5. Attract students to explain these ideas;
(4) Consolidate and deepen, and question and expand.
Basic exercises:
Do it on page 55.
Analyze the questions by yourself and then answer them.
Teacher: What other questions can I ask?
Students choose their own questions and answers and tell each other why they are doing this.
Variant exercise:
Complete the question in exercise 12 on page 56 1.
1. Let the students look at the picture carefully. What small animals are drawn in the picture? How much is the difference?
2. Analyze and solve by yourself: How many times are deer more than monkeys? (The formula is: 18 ÷ 6 = 3)
3. Q: Why is this format?
Teacher: Can you ask other questions? (Students understand each other)
(5) class summary:
What did you learn from this course?