Unit 1 Division with Remainder
Unit plan
Instructor: Niu Hong Ying
Teaching material analysis:
The content of this unit consists of three parts. 1-2 has a preliminary understanding of the meaning of remainder and division with remainder. On page 3-4, there is vertical calculation of remainder division in the preliminary teaching. I understand that the remainder must be less than the divisor. Page 5-7 Practice division with the remainder, strengthen the concept, master the algorithm, and solve the average score problem with the remainder. How to find quotient is the most critical step in calculating division with remainder. Teaching materials guide students to experience the method of seeking business through examples. Arrange from easy to difficult. Divide one digit by one digit first, and then divide two digits by one digit. From intuition to formal concealment, first you can see the quotient on the diagram, and then you don't show it on the diagram. In terms of methods, it is the combination of image thinking and abstract thinking to understand the thinking of seeking business.
Analysis of learning situation:
Let students first form the representation of "remainder" in the activity of dividing things, and then gradually establish the concepts of remainder and division by remainder. It is not surprising that students have some problems or even mistakes when they use remainder division to find quotient. We should make full use of these setbacks and mistakes as teaching resources, so that students can try methods and essentials in the process of error correction.
Teaching objectives:
1. Make students go through the process of abstracting the phenomenon that there is a remainder after the average score as a division with a remainder, initially understand the division with a remainder and the meaning of the remainder, explore and master the method of quotient of the division with a remainder, know that the remainder is less than the divisor, calculate the divisor vertically and use the division with a remainder to solve related simple practical problems.
2. To enable students to further accumulate experience in observation, operation, communication and other learning activities, develop the ability of comparison, analysis, abstraction and generalization, and enhance their awareness of mathematical application in the process of understanding division with remainder and exploring the calculation method of division with remainder.
3. Make students further feel the close connection between mathematics and life, and understand the development context of division meaning and the rationality of calculation method; In the process of exploring calculation methods and discovering mathematical laws, we should strengthen the willingness to cooperate with others, cultivate the attitude and habit of actively participating in activities, and establish confidence in mathematics.
Difficulties and emphases in teaching:
Teaching focus:
1. Understand the meaning of division with remainder and calculate division with remainder.
2. Be able to use the knowledge of division with remainder to solve related practical problems.
Teaching difficulties:
A divisor is a method of dividing a digit by a quotient.
Class arrangement:
Division with remainder 2
Exercise 1 3
Comprehensive exercise 2
The first lesson: understanding of remainder division
Instructor: Niu Hong Ying
Teaching content: Thinking and Doing, page 1, page 2, question 1 ~ 3.
Teaching objectives:
1. Know the remainder in the activity of dividing several objects equally and understand the meaning of remainder division.
2. Can write the division formula according to the situation that the average score is surplus, can correctly represent the quotient and the remainder, and can correctly read the division formula with the remainder.
3. Cultivate the ability of observation, analysis, comparison, synthesis and generalization through the organic combination of operation, thinking and language.
4. Feel the close connection between mathematics and life, and realize the significance and function of mathematics.
Teaching emphasis: abstract the phenomenon of surplus after average score into division with surplus.
Teaching difficulty: understanding the meaning of division with remainder.
Teaching process:
First, talk before class.
1. Say: Happy New Year, children! Today is the first math class of the new semester, and it is also the first time for teachers to tutor children. I hope we can cooperate with each other in the future study. We can study together and make progress together, ok?
2. Oral calculation: 16÷4= 48÷8= 30÷6= 56÷7=
24÷3= 45÷9= 25÷5= 64÷8=
Q: Which formula did you think of?
Second, the introduction of new courses.
Dialogue: We already know that we can divide some objects equally, but sometimes we can divide some objects equally, and sometimes we can't. This is the new content to learn today, blackboard writing: division with remainder.
Third, the new teaching curriculum
1. Ask questions.
(1) During the Spring Festival, a child came to Xiaohong's house to be a guest, and her mother took out a 10 pencil. She wants Xiaohong to take the exam, and her mother wants Xiaohong to share 10 pencils with the guests. Let the children help Xiaohong advise how to divide it reasonably.
(2) Students are free to express their opinions and guide students to have a unified understanding: everyone gets the same amount.
(3) Conversation: Everyone gets the same amount. How to divide it? (2 per person, 3 per person, 4 per person ...)
Everyone divides into two branches. How many people can you give? Everyone is divided into three branches. How many people can you give? Everyone is divided into four branches. How many people can you give? ..... The classmates at the same table took out the 10 branch representing ten pencils and filled it in the table on the first page of the book.
2. Explore new knowledge.
(1) One point (show the record sheet)
How many branches are given to everyone, and how many are left?
2
three
four
five
six
Students' autonomous activities and teachers' inspection.
Collective communication: If everyone is divided into three branches and everyone is divided into four branches, how many people will they give to each other? Teachers exchange answers while demonstrating.
(2) Say it out
① talk: observe the main points, classify and talk about your own views?
② Summary: The average score of 10 pencil has two different results: one is that it has just been written, and the other is that there is a surplus after the score. Show me the form:
Table (1) Table (2)
How many branches are there left for everyone? How many branches are there left for everyone? How many branches are there left for everyone?
2 5 3 3 1
5 2 4 2 2
6 1 4
(3) Write the formula
① Observation table (1)
Question: 10 pencil is divided into 2 pencils each. How many people can you give them? Have you finished dividing it? How to calculate in the form of columns?
Blackboard: 10÷2=5 (person)
10 pencils are divided into 5 pencils each. How many people can you give them? Have you finished dividing it? How to calculate in the form of columns?
Blackboard: 10÷5=2 (person)
Q: Can you name some of these two formulas? Is there any other way to divide it like this?
② Observation table (2)
Dialogue: 10 pencils are divided into 3 pencils each. How many people can you give them? Is there any way to calculate? (Blackboard: 10÷3) How many people can I share? Have you finished dividing it? How much is left? Can this 1 branch be divided?
Important: This 1 pencil is left, which is a part of 10 pencil. Don't forget, put a dot behind the three people and record it! Blackboard: 10 ÷ 3 = 3... 1
③ Cognition and number. In the division formula, each number has its own name. 10 ÷ 3 = 3... 1, 10, 3, 3 What are their names? 1 If you don't know, read a book quickly and see which child found it first.
Feedback communication, the whole class reads the formula: 10 divided by 3 equals 3, 1.
④ Speaking: 10 pencil is divided into 4 pencils each. How many people can you give them? Is there any way to calculate? (Blackboard: 10÷4) How many people can I share? Have you finished dividing it? How much is left? Can these two branches be divided?
⑤ Dialogue: 10 pencils are divided into 6 pencils each. How many people can you give them? Is there any way to calculate? (Blackboard: 10÷6) How many people can I share? Have you finished dividing it? How much is left? Can these four branches be divided?
Emphasis: Every time the number of branches is not enough, there is a remainder, so the remainder must be less than the divisor.
(4) Summary: Think about it. Under what circumstances can the average score be expressed by division with remainder? What does the remainder mean?
Fourth, application expansion.
1. Question 1, "Think and do", ask students to put a pendulum with their own learning tools as required, and then fill in the blanks according to the results of the pendulum. When correcting collectively, let the students talk about what the quotient and remainder in each question represent respectively.
2. Students independently complete, teachers patrol and collectively correct.
3. Observe and compare the similarities and differences between these two problems.
Fifth, summarize the whole class.
1. What did you learn in this class? Tell your partner!
2. What do you think should be paid attention to in today's new lesson? What other situations in life have a surplus after the average share?
3. Is there anything you don't understand?
Six: Extracurricular development
Go home and take out 12 candy and distribute it to several people equally. Everyone gets the same amount. How many ways are there? Write a division formula for each division and see how many formulas are divisions with remainder. I will tell you tomorrow.
The second lesson: the calculation of remainder division
Instructor: Niu Hong Ying
Teaching content: Thinking and Doing, pages 3 and 4, 1 ~ 4.
Teaching objectives: