Teaching objectives:
1. Combined with the specific situation and experience of "one point, one point", abstract the division formula and realize the significance of division operation.
2. Master the reading and writing of the division formula and remember the names of each part of the division formula.
3. Will use the division formula to express and explain the specific process of average score.
Teaching focus:
Use division formula to express the process and result of average score, and understand the meaning of division formula.
Teaching difficulties:
Use the division formula to express the average score.
Teaching process:
First, fill in the points and pave the way for review.
1. Fill in the blanks:
Three () Twelve () Sixty-two () Eighteen () Sixty-eight
2.
(1) Give it to three people, each with ().
(2) each person is divided into three parts, which can be distributed to () people.
Second, hands-on operation, explore new knowledge.
Teacher: One day, mother monkey bought 12 bananas, and she wanted to give them to brother monkey and brother monkey, so that they were both satisfied. How should a female monkey divide bananas?
Student: Average score. (Blackboard Book: Divide 12 bananas into 2 parts on average, and each part has () bananas. )
1. Magnets replace bananas for one point.
Teacher: Now the teacher draws two circles on the blackboard to show that there are two monkeys, using magnets instead of bananas. Who wants to go on stage to help divide bananas?
Teacher: We saw that each monkey was given six bananas, and each monkey had the same number, that is, the average score.
2. Know the writing, reading and name of each part of the division formula, and understand the meaning of the division formula.
Teacher: The process of sharing equally like this can be expressed by division. 12 ÷ 2 = 6 (root)
Teacher: Note that there is a new mathematical symbol in this formula, which is called "division symbol". You see, there is a horizontal line in the middle and two points up and down.
Teacher: Students, which one of you can read this formula?
Health: Twelve divided by two equals six. Students read after it twice.
Teacher: Now, who can tell us what each part of this division formula stands for?
Health: 12 means there are 12 bananas, the division symbol means the average score, 2 means the average distribution to two little monkeys, and 6 means that each little monkey gets 6 bananas.
Teacher: So what does the divisible formula mean?
Health: This formula means that 12 bananas are equally distributed to two little monkeys, and each little monkey is divided into six parts.
3. Introduce another meaning of division formula.
Teacher: Now the mother monkey has asked the little monkey to put every four of these 12 bananas into 1 plate. How many plates do you need? (Blackboard book: Every 4 bananas contain 1 plate, and () plates are needed. )
Teacher: It can be seen that a * * * needs three plates, which can be divided into 12 bananas.
Teacher: Is this grading process an average score?
Health: Yes.
Teacher: Then we can still use division to express the result of division just now. 12 ÷ 4 = 3 (pieces)
Students read this formula once.
Teacher: Tell me what each part of this division formula means.
Health: 12 means there are 12 bananas, division means the average score, 4 means there are 4 bananas in 1 plate, and 3 means three plates are used.
Teacher: What does the whole formula mean?
Health: Put 12 bananas into 1 plate for every 4 bananas. Need three plates.
Teacher: We all know that all parts of addition, subtraction, multiplication and division have their own names, and all parts of the same division formula also have their own names. Do you know what they are called?
Teacher: (Summary) The number before division is called dividend, the number after division is called divisor, and the result of division is called quotient.
Teacher: We solved these two problems by division just now. Why can we solve them by division?
Summary: In the future, you will encounter the problem of average score, such as how much each share is, or how many shares are divided, which can be solved by division.
Third, practice and expand your thinking.
1 and 12 How to divide bananas equally? Represented by the division formula. Students work in groups and communicate with the whole class. )
2. Look at the pictures and fill in the blanks: (The students helped the little monkey solve the problem, and the little monkey took out some fruits to thank everyone. ) Show me the fruit map.
(1) 12 strawberries, divided into three parts on average, each with ().
(2) Divide 15 apples into 3 parts, each part is ().
3. Allocate 18 bones to 6 puppies on average. How many bones does each puppy have?
4. There is a pile of apples, which are distributed to five monkeys on average and have just been eaten. Guess how many apples are there in this pile?
5. Try a 38-page math book.
Fourth, summarize and review.
What did you learn in this class, children?