1, initially learn to use division with remainder to solve simple practical problems in life.

2. Learn to answer simple questions with remainder correctly, and you will write the unit names of quotient and remainder correctly.

3. Cultivate students' ability to collect information, analyze and solve problems.

Emphasis and difficulty in teaching

Teaching emphasis: using the knowledge of division with remainder to solve simple practical problems.

Teaching difficulty: understanding the application of division with remainder in real life.

teaching tool

Ppt courseware

teaching process

First, check the import.

1, oral calculation

14? four

22? six

36? seven

47? five

39? nine

2. List the formulas first, and then answer the following questions.

(1), 17 apples, one for every five, can hold () apples, and there are () apples left.

② 4 yuan for each box of drinks, 19 yuan can buy () boxes, with () yuan left.

It seems that everyone has mastered it really well! Today, we will learn how to use remainder division to solve problems in life! (blackboard writing topic: solving problems)

Second, explore new knowledge.

1, showing the theme map (Example 5)

Teacher: Students, what are these children doing in the picture? Health: Rowing.

Teacher: What mathematical information can you find from the picture?

Health: There are 22 people rowing, and each boat can take up to 4 people.

Teacher: What do you mean, four people at most? I don't understand. Who can help the teacher?

Health: You can take 1 person, 2 people, 3 people and 4 people, but you can't take 5 people.

Teacher: Oh, thank you for your clear explanation. You got it? Seating four people at most means sitting 1 person, two people, three people, and only four people at most.

Teacher: What's the math problem here? Did you find it?

Health: How many boats should I rent at least?

Teacher: You found the right one. Can you help the teacher explain the minimum value here?

Health: It means the least.

Teacher: Oh, how many boats should I rent at least? Who can talk about this topic completely now?

Health: 22 people row a boat, and each boat can take up to 4 people. How many boats should we rent at least?

Teacher: If there are six people going boating, how many boats are needed for each boat arrangement 1 person? How about two people? What about three people? What did you find?

Health: I found that the more people sit on each boat, the fewer boats are used.

Teacher: Then how many people should be arranged on each boat here to use the least number of boats?

Health: Full staff, that is, four people.

Now please answer this question with pictures or words.

Student 1 show: I used four circles instead of four people, * * * used five boats, and there were two people left.

Student 2: I use a big circle instead of the boat, and write 4 directly in it, which means there are 4 people sitting, and there are 2 people left.

Student 3: I calculated vertically, 22 people, 5 people in each boat, 20 people, and there are 2 people left.

Teacher: Thank you for providing us with such a good solution! Now can you work out the formula according to her method?

Health: 22? 4=5 (Article) 2 (Person) Teacher: Why do you use division? Student: Because the division of four fours means how many fours are in 22, so we use division?

Now we have solved this problem by formula. So how many boats should we rent at least? Health 1: 5 health 2:6.

Teacher: It seems that the remaining two people are the key! So what should the remaining two people do?

Health 1: The remaining two people should rent another boat. Health 2: I also think the remaining two people need to rent another boat!

The teacher concluded: If the remaining two people were you, would you be happy not to let you go? If we want to go together, we have to rent another boat! So we will use 5+ 1=6 (bar).

Step 2 transport pineapples

Teacher: You are tired of rowing. Are you thirsty? Uncle Wang prepared pineapples for us. Who can read them?

Read the questions for the students.

Free form formula!

Student demonstration: 27? 8=3 (times) 3 (boxes) 3+ 1=4 (times)

Teacher: Why did you add 1? Health: Because the remaining three cases will be shipped separately again.

The teacher concluded: When dealing with the remainder like this, we add 1 to the quotient, which is called one-step method.

Step 3 buy bread

Teacher: Students, Uncle Wang also prepared soft bread for us. Look at the picture. Do you think it's weird?

Health: A loaf of bread is 3 yuan.

Teacher: Show me the question. 1How many can 0 yuan buy at most? Please list the formulas and explain the reasons.

Health: 10? 3=3 (block) 1 (yuan) because the remaining 1 yuan can't buy a loaf of bread.

Teacher: Like this, the remainder has no effect on quotient, so just remove it. We call it tail-cutting.

4. Comparative summary

Do you treat the rest in the same way when rowing and buying bread? Why?

Health: Because the other two rowers are leaving, the remaining 1 yuan can't buy a loaf of bread.

Teacher's summary: these two are different practical problems, so we should deal with the remainder in combination with the reality in life.

Third, consolidate the practice.

1, judge (explain the reason)

Aunt Li sewed a coat. How many coats can be nailed with 7 buttons and 38 buttons?

38? 7=5 (pieces) 3 (pieces)

5+ 1=6 (pieces)

Answer: 38 buttons can nail 6 buttons. ( )

2. Which of the following questions have been selected? Tailing method? Or? Become law?

(1) How many pieces of 2m cloth and 7m cloth can be made? ( )

(2) A box of 8 with 50 cream cakes. How many boxes should I use at least? ( )

3.8 yuan plays a merry-go-round, how many times can 50 yuan play it?

Fourth, class summary.

Can you talk about your own gains through the study of this course?

Health 1: I know what to do with the rest. Become law? And then what? Tailing method?

Health 2: I know that I should consider the practical problems in my life when dealing with the rest.

Write on the blackboard.

Division with remainder

solve problems

22? 4=5 (Article) 2 (Person)

5+ 1=6 (strips)

A: At least six boats must be rented.

Teaching plan of remainder division (II) Teaching objectives

Knowledge and skills: through observation and operation, let students understand and master the ideas and methods to solve problems related to regular arrangement.

Process and method: Experience the whole process of solving problems by using the knowledge of division with remainder, further understand the diversification of problem-solving strategies and methods, and develop application consciousness.

Emotion, attitude and values: experience the connection between mathematical knowledge and accumulate basic experience in solving problems.

Emphasis and difficulty in teaching

Teaching focuses on understanding and mastering the ideas and methods to solve problems.

Difficulties in teaching: Understand the function and significance of remainder in solving problems related to regular arrangement, and solve problems.

teaching process

1. Query and stimulation, game introduction

1.？ Guess your finger? match

Rules of the game: stretch out your right hand and count from your thumb. 1 is thumb, 2 is index finger, 3 is middle finger, 4 is ring finger and 5 is little finger. After counting, go back to your thumb and count 6, 7 and 8 in turn. Don't show it to the teacher. When you count a number, ask the teacher to guess which finger the number is on.

The number of students, the teacher guessed

2. Introduction to questions

Teacher: Is the teacher right? Do you know the mystery? Ok, today we will study this kind of problem. (blackboard writing topic)

2. Observe and explore new knowledge.

1. Obey the law and ask questions

Teacher: This is a picture of a small flag. Please observe carefully. What are the rules of flag? (showing pictures)

Health: Put them in groups, yellow on one side and red on both sides.

Teacher: Think about it. What color is the next 10 face? 1 1 face? 12 face?

Health: 10 face is yellow, 1 1 face and 12 face are red.

Teacher: According to this rule, what color should the 16 flag be?

2. Explore independently and solve problems.

Teacher: Please find a way to solve this problem yourself. You can draw a picture and write it on paper. After writing, you can communicate your method with your deskmate first, and pay attention to express your method clearly.

Students operate and teachers patrol.

3. Presentation and discussion.

Teacher: Who will show your research results?

Student: I use painting to express it. 16 flag is yellow.

Teacher: What rules do you follow?

Health: Circle it with a yellow flag and two red flags.

Teacher: The student shows the rules by drawing. It seems that when solving this problem, we can list them one by one on the basis of discovering the laws and get the results.

Teacher: Is there any different way?

Student: That's what I said. 16 flag is yellow, too.

Yellow, red, yellow, red, yellow, red, red, yellow, red, yellow.

3 6 9 12 15 16

Teacher: This student is represented by Chinese characters and numbers. You got it?

Health: He uses Chinese characters to indicate the rules of flags and numbers to indicate the number of flags.

Teacher: This student uses Chinese characters to show the rule of flag arrangement, and uses the method of array to get the result.

Teacher: Is there any other way?

Health: I calculated it continuously. 16? 3=5 (group)? .. 1 (face), 16 face flag is yellow.

Teacher: Can you tell the students what the numbers here mean?

Health: 16 is the number of flags to be arranged, 3 is a group of three, 5 is a group of five, 1 is the number of flags left after five groups.

Teacher: What numbers do you use to judge the color of the national flag?

Health: The remainder is 1.

Teacher: Why is the remainder 1 and the color of the flag yellow?

Health: Because the flags are arranged in yellow, red and yellow, the remaining 1 is the first flag in this arrangement, so it is yellow.

Teacher: Students, what if the remainder is 2? What color is the national flag?

Health: red.

Teacher: It seems that the color of the last flag is determined by the remainder. What is the remainder? The result is the first in this group.

4. Change the data and build the model.

Teacher: What about the 27th side? What did you find?

Health: 27? 3=9, 27 flags are exactly divided into 9 groups, and the last flag is red.

Teacher: The color of the last flag is determined by the remainder, which has nothing to do with business. What is the remainder? The answer is which one in this group. If there is no remainder, it means just finished, and the answer is the last one in each group.

Third, consolidate the practice.

Teacher: Now, please finish the classroom exercises.

1. Finish the exercise on page 69 of the textbook 15, question 4.

Students read and examine the questions by themselves, answer the questions independently, and exchange answers collectively.

2. Finish the exercise on page 70 of the textbook 15, question 6.

(1) Small questions are solved by students themselves; (2) Small questions combined with monthly calendars guide students to understand the relationship between quotient and remainder and this question.

Fourth, reveal the game, class summary

Teacher: Now, students must know that they are getting old, right? Guess your finger? Its secret. Now, in turn, the teacher counts and you guess. (Teacher-student activities)

The teacher concluded that many problems in life can be solved with the mathematical knowledge we have learned. I hope students are good at finding and solving these problems.