The first lesson: understanding of remainder division
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.