Teaching objectives:

1. Make students go through the process of exploring the calculation method of 8, 7 plus several, and can calculate correctly.

2. Make students gradually cultivate the consciousness and habit of exploration and thinking in observation and operation. Cultivate students' innovative consciousness through algorithm diversification.

3. Enable students to use knowledge to solve practical problems in life, understand the role of mathematics, and initially cultivate the application consciousness of mathematics. Teaching process:

First, the game guides people and stimulates interest.

Do you like playing games, children? Now let's play, shall we?

The teacher clapped his hands and said rhythmically, let me ask you, little friend, how much is 9 plus 10?

Student: Miss Shao, let me tell you that 9 plus 1 equals 10. ...

[Comment: The relaxed and pleasant classroom atmosphere has laid a good foundation for the teaching of the new curriculum. The composition of 10 not only reviews password games, but also provides a basis for students to explore the algorithm of 8 plus 7. ]

Second, the operation of inquiry, learning new knowledge

1. Teach trumpet drawing.

(1) Question: This is a thumbnail. Who can explain the meaning of this painting?

Can you ask a question of addition calculation? How to form?

[Comment: Let students talk about ideas first and then ask questions, aiming at cultivating students' ability to collect information and ask questions. ]

(2) Question: What is 8+7? Can you see it from the picture? Talk about it in the group.

(3) Who will tell me what you think? "

Students may have the following ideas when communicating:

(1) a "number.

② Eight plus two on the left is 10, 10 plus five is 15.

③ Seven plus three on the right is 10, 10 plus five is 15.

(4) There are 20 boxes * * *, and now 5 boxes are empty, which is 15.

⑤8+7=8+2+5= 15。

⑥8+7=7+3+5= 15。

Students demonstrate the process of trumpet movement through computer animation when communicating the second and third methods.

[Comment: Teachers make full use of thematic maps to let students explore 8+7 calculation strategies independently. The above different algorithms reflect students' three cognitive levels: the first algorithm shows a tendency to grasp actions, and the cognitive level needs to be improved; The second algorithm shows a tendency to grasp graphics, and such students have strong observation and imagination for graphics; The fifth algorithm shows a tendency to grasp symbols. These students have abstract thinking ability and high cognitive level. ]

2. Teaching stick figures.

(1) The children have come up with many ways to calculate 8+7 = 15. Want to know what small green peppers and mushrooms think?

Put a stick on the small green pepper. Please talk in the group. What's it thinking? Say its name.

Animation demonstration, students fill in the numbers in the box.

(2) The ideas of small mushrooms and small green peppers are a little different. Please talk in the group. Communicate by name.

[Comment: Setting up the situation of helping small green peppers and mushrooms, and asking students to fill in the numbers in the box is conducive to cultivating students' virtue of helping others, and at the same time making students' cognitive level develop on the original basis. ]

(3) What's the difference between these two methods? Like what? Summary: These two methods are "add up to ten methods". 3.( 1) Teach the problem of "think and do it" 1.

Please put it with your school tools before calculating. Students talk after they finish speaking.

(2) (The computer shows the second question "Think about it and do it") Let's play a game of "Circle Ten". Circle 10 first, then calculate.

(3) teaching "think about it". Question: Do you think so without looking at the picture or putting a stick? Please fill in this book.

Question: What other related formulas can you think of when calculating 8+9? "

Somebody say something. Students may think:

① Because 9+8= 17, 8+9= 17.

② Because 9+9 = 18, 8+9= 17.

③ Because 8+ 10 = 18, 8+9= 17.

④ Because17-9 = 8,8+9 =17.

[Comment: Let different students show different thinking processes, let them have a positive learning experience, feel the happiness of success, and further develop their creative thinking. ]

(4) Summary: When we calculate 8+9, we can think of the formula we learned before. This method is really good. (The computer shows "Think and do" Question 4) Can you quickly calculate the number of these questions?

Students answer orally.

[Comment: Through the comparison of problem groups, students realize that if a small number is added to a large number, the number can be directly calculated by the formula they have learned, and at the same time, they realize that the two numbers are added, the positions are exchanged and the sum is unchanged. ]

Third, look for laws and consolidate new knowledge.

1. The computer shows the question "8 plus a few", and the students answer it orally, leading them to find that if you divide the added number by 2 plus a few, you will know that the number is more than ten. Summary: If this rule is discovered, it will be correct and soon.

[Comment: Providing students with rich learning materials, let them observe and compare, so as to find the law of 8 plus several, which can not only improve students' oral calculation speed, but also cultivate students' habit of inquiry and thinking. ]

2. The computer shows the title "7 plus children". Question: So, is there such a rule that seven plus several? Who can quickly calculate the number of these questions?

3. Organize an oral contest, with one representative for each boy, one representative for each girl and the rest gesturing.

Fourth, contact life and solve problems.

Question: It's not enough to know what it is. We should learn to use our brains and use what we have learned to solve problems in life. You see, there are three bags of bread in the bakery. The first bag has nine bags, the second bag has eight bags and the third bag has six bags. Aunt Wang in kindergarten is going to prepare snacks for the children in the class 15. Which two boxes do you think are more suitable? Organize students to communicate on the basis of independent thinking.

Conclusion: Applying mathematical knowledge can solve problems in life. Moreover, as long as you are willing to use your head, there are often more than one way to solve the problem.

[Comment: The teacher raised a challenging question from real life, which requires students to make analysis, estimation and judgment in specific situations. The process of solving problems makes students get the joy of success, at the same time, it also enhances their confidence in learning mathematics, develops their thinking of seeking differences, and cultivates their attitude of seeking truth from facts and innovative spirit. ]

General comment: There is no rigorous explanation of calculation methods and repeated standardized arithmetic language training in this course. Teachers allow students to think in a form suitable for their own thinking characteristics, explore calculation methods, and form general strategies to solve problems. Students have acquired basic mathematics knowledge and skills, and at the same time fully developed their emotions and attitudes. Students' learning activities are a lively and personalized process.