First, create situations to stimulate interest and inspiration.

Teacher: Congratulations to the students for winning the grade championship in the autumn sports meeting. Do you usually like doing sports?

Now the teacher will take the students to a primary school playground to watch the sports meeting? However, only by successfully crossing the border can you get tickets for the visit. Come on!

Quick answer: 9+ 1+n, Q: How do you calculate so fast?

Children, you not only answered this set of questions correctly, but also found the rules. We got the tickets. Let's go!

Design intention: This exercise is to make students realize that 9+ 1= 10 and 10 plus a few equals more than ten through oral calculation, so as to fully pave the way for the application of the "ten-supplement method".

Second, participate independently and explore new knowledge.

1. Observe the theme map and try to talk about the algorithm. The courseware shows the panorama of the textbook on page 88. )

Teacher: Look, how lively the playground is! What sports have you observed? Let the students speak freely. Then the teacher focused the students' attention on the milk map with multimedia, and asked the students to observe the milk map carefully and tell what mathematical information was collected. According to this information, a mathematical problem is put forward.

Presupposition: Students may say, "How many boxes of milk are there in a carton?"

The teacher asked: Tell each other at the same table how you know how many boxes of milk are in a * * *? (teacher patrol collection algorithm)

Default method 1: Students can use counting method and receiving method;

Default method 2: composition method;

Default method 3: make up ten methods;

If there is a way to make up ten, the teacher asks: how to make up ten? Ask the students to demonstrate with school tools and say how to make up ten. Then I asked: Who used this method? Ask 2-3 students to talk about the process of putting the ten together completely, and then the teacher intuitively demonstrates the children's thinking process with courseware: take one of the four boxes outside and put it into the box to make 10 boxes, and the 10 boxes in the box and the three boxes outside the box add up, and a * * * is 13 boxes. Make students have a preliminary impression of "10 plus 9".

Design intention: The curriculum standard points out that "students have to go through the process of knowledge formation", so I didn't directly tell students how to calculate 9 plus several in this step, but through exploration, communication and reporting, let students gradually form an understanding of mathematical methods and feel the diversity of algorithms.

2. Optimize the algorithm and summarize.

Teacher: Which method do you like best and why? "

Design intention: Students gradually discover which method is the simplest and which method has defects through comparison. So as to achieve the purpose of optimizing the algorithm.

(2) Guide students to sum up the arithmetic of "add up to ten"

Students put a small disk and count it as 9+4. Say a * * *. How do you count how many small disks there are?

Design intention: Let the students try to move the small disc by themselves and complete the process of rounding up ten. Make students form the appearance of making up ten in their minds and deepen their understanding of the methods of making up ten.

Then guide the students to say, "Take a few, take a dozen." And asked: 1 Where was it taken? Strengthen the process of rounding ten, and answer the blackboard according to the students.

Design intention: In the process of preparation, I collected some students' ballads, such as: in order to make 90% ten, divide 4 into 1 and 3,9 plus 1 equal to 10, 10 plus 3 equal to13; See 9. It is considered that 1 equals ten, and 4 can be divided into 1 and 3,9 plus 1 equals 10, 10 plus 3 equals 13 and so on. The first-year students are young, which requires them to think, be intuitive and abstract, and express the process of making up ten in words, which is a heavy burden. So I simplify the calculation to "take a few and take ten", which is simple and clear, reduces the burden on students and helps to improve classroom efficiency.

3. Consolidate algorithms and infiltrate ideas.

Ask the students to put the calculation process of 9+6 and 9+3 on a small disk and report it by name.

Design intention: Through several operations, observation and dictation. Enable students to integrate operation, thinking and language to achieve the purpose of deepening arithmetic. Make students know not only why, but also why.

Let the students observe the formula on the blackboard and exchange their findings at the same table? According to the students' report, draw out the questions and write them on the blackboard.

Then ask: how do we add 9? According to the students' answers, use arrows to connect the formula of 9 plus several with 10 plus several, which is permeated with the idea of reduction.

4. Consolidate new knowledge and look for laws.

Ask the students to say that there are 9 plus several formulas. What are the other formulas? Teacher's blackboard 9+2= 1 1, 9+3= 12, 9+4= 13, Pan & gt9+5= 14, 9+6 =/kloc-0. Let the students think independently first, then communicate in groups and report collectively.

Third, apply new knowledge to solve problems.

(1) Basic exercises.

1. Quickly add a few to 9 with regularity. Ask the students to answer the oral calculation of 9 plus several quickly.

2. Circle the union number.

(2) Comprehensive exercises.

1. Let's play. Timing, quick calculation, adding a few words to 9.

2. Fill in 2, 3, 4, 5, each number can only be used once, so that each row is 16.

The third level: improve practice.

Find a rule to fill numbers. Think about it, how much is hidden under the question mark? Create exhibition space for students who have the spare capacity to study.

Design intention: In order to consolidate the knowledge I have learned and improve my understanding of the calculation of 9 plus several, I pay close attention to the key points in the exercise design, not only paying attention to following the students' cognitive laws step by step, but also paying attention to the training of students' thinking, integrating theory with practice and putting the cultivation of students' learning ability into practice.

Fourth, talk about harvest and infiltrate the soul.

Let the students talk about what they have learned from this class first. Then the teacher guides the students to summarize the class.

Design intention: This link timely and appropriately infiltrated the idea of mathematical transformation, activated students' thinking, and urged students not to flinch when they encounter problems in their future life and study. They must use their brains to find ways to turn their own problems into their own knowledge, and believe that they will be able to overcome difficulties and succeed! .