First, teaching material analysis:

"Simple Cycle" is the teaching content of the fifth unit of the fourth grade primary school mathematics (Volume I) in the curriculum standard textbook of Jiangsu Education Edition. The key and difficult point of this lesson is to determine what object or figure a serial number represents according to the arrangement law of objects.

The teaching objectives are:

1. Let the students explore and discover the arrangement law in simple periodic phenomena according to the specific situation, and determine what object or figure a serial number represents according to the law.

2. Let students actively experience the process of independent exploration, cooperation and communication, and experience different problem-solving strategies such as drawing, enumerating and calculating.

3. Let students experience the connection between mathematics and life in the process of exploring the law and get a successful experience.

Second, teaching methods and learning methods:

1. Create a situation conducive to students' independent inquiry, attach importance to students' independent inquiry, and understand different problem-solving strategies.

2, create an atmosphere of cooperative learning, encourage them to cooperate with each other, * * * improve.

3, combined with life, let students feel the meaning of mathematics in life in the process of applying mathematics knowledge.

Third, teaching ideas

According to the characteristics of the textbook, I designed six main teaching procedures: the first part introduces new lessons through cartoon animals that students are familiar with and interested in; The second part explores the law independently in the real situation; The third part, through different exercises and methods, improve students' methods to solve such exercises; The fourth part is to use law to analyze and solve some practical problems in real life; Consolidate and deepen students' understanding of the law. The fifth part is to summarize and evaluate, extend the law, appreciate and introduce some laws existing in life. The sixth part is a game to expand students' thinking.

1. Create the situation and draw out the rules.

At the beginning of the class, I first show the beading activities that students are familiar with, first string green, then string yellow, blue and red beads, and then show a group in turn, so that students can guess what color beads I will string next. In fact, the students have realized that I string in a certain order, that is, there are certain rules, so they can quickly guess the color I want to string next. Then point out that today we are going to find the rules together. Let the students know the learning tasks of today's class first. [Use beading activities to stimulate students' interest. After I show the two groups, the students have established the appearance of regular arrangement in their minds. Students can guess correctly and further perceive that the arrangement of objects is regular. Thus, this perception is applied to the diagram, so that students can find out the law. ]

Show the sample pictures, let the students observe and talk about what is in the scene, feel the objects such as colored lights, flags and potted flowers, observe the placement of these objects, and talk about your findings. From the observation of these objects, it is found that the placement of these objects is regular. It is precisely because these objects are arranged neatly and regularly that they are so pleasing to the eye, allowing students to appreciate the beauty of mathematics and effectively stimulating their enthusiasm for exploring the law independently. Here, I only asked students to talk about their own placement rules, but I think this rule should be demonstrated in the courseware, so I added some circles to express it and reached a unified understanding. ]

2. Explore independently and understand the law.

This link is the focus of this course. First of all, the multimedia presentation questions are put like this. From left 19 What color are the flowers in the pot? After understanding the meaning of the question, let the students operate by themselves and express their ideas.

In this process, I give students enough time to think independently and explore strategies to solve problems independently. Because different students are different in many ways, students come up with many ways. Some students draw a blue flower by drawing. All these methods can answer this question. But I mainly discussed the calculation method proposed by students. Use 19÷3=6 (group) ... 1 (basin). According to this formula, let the students say what 1 9,3,6 and the remainder1mean. The students made it clear that1* * has 19 potted flowers, a potted blue flower, a potted yellow flower and a potted red flower as a group, and * * * one more potted flower is divided into 6 groups. I asked a question. According to this formula, how do you judge that it is a blue flower and lead the students' focus to the remainder? I realized that 19 potted plants belong to the seventh group 1 potted plants, because the flowers in each group are the same, so just look at the color of the first pot in each group. [In the process of explaining, I also circled 19 pots with courseware, and divided every 3 pots into 6 groups, so that the students could know at a glance that the remaining pot was the first pot of Group 7. ]

When exploring the arrangement of potted flowers, students were given enough time to think independently and explore strategies to solve problems independently, thus developing their innovative consciousness. Show various problem-solving strategies through full communication. And pay attention to guide students to constantly optimize the strategies to solve problems. ]

3. Try and choose a method independently

Next, I let the students continue to explore and solve the 1 problem of colored lights in their favorite ways. In the communication, some students still use the method of drawing, and some use the method of calculation. Then I asked, why not use the method of inference? Let the students understand that the inference method is only applicable to the regular arrangement of two objects as a group. So the simplicity of this method is ruled out. Then ask the students what color is the 20th light? This time, most students realized that drawing was very troublesome, so it was logical to guide them to use calculation methods to realize the simplicity of calculation. Among them, there is no remainder in the formula for finding the color of Lantern 23. Here, students should focus on understanding and talking about the meaning of non-residue, so that students can roughly understand the judgment methods when there is residue and when there is no residue. Here, what the courseware originally shows is to use circles with different colors instead of colored lights to reflect its law. Now I think it is clearer to show it directly on this map and it is easier for students to understand. This small topic focuses on letting students judge and appreciate the simplicity of calculation with formulas. Then I directly asked the students to calculate the colorful flags with formulas, and asked them to observe these formulas and find out the law of numbers after they finished. When the number is, it is the color of the flag in each group. Here, I also think that the rule of displaying colorful flags with circles on the map is more obvious. Because here I found that several students still think that this is a set of two flags, which is relatively clear.

Next, I will show the definition through the arrangement of three questions: the phenomenon that the same thing repeats in turn like above is called periodic phenomenon. Then I asked my classmates, can you give an example of periodic phenomenon in life?

After the students answer, the teacher shows the pictures for appreciation (periodic phenomenon in life)

Fourth, the summary, expansion and extension of the whole class.

Summarize the whole class, let the students talk about your feelings and gains. If you want to say anything, tell the students that the rules of learning today are cyclical, and such rules can be solved by calculation. Then let students appreciate some laws in life, appreciate their beauty and apply them in life, and cultivate their sentiments at the same time. Students are very interested, but the key is to let students learn to use knowledge to solve problems.

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