Determination of teaching objectives:

On the surface, it is necessary to master the calculation formulas of cuboids and cubes. But more important than this goal is to understand the ins and outs of the calculation formula. Is to clearly establish the derivation process of the formula in your mind. This is to develop students' mathematical thinking. Specifically, it is to develop students' spatial imagination, association, reasoning and proof. This is the so-called mathematics education, and the key point is to develop students' mathematical thinking. It is a sign that students should establish contact between mathematical knowledge, from fragmented mathematical knowledge to networked knowledge structure, from surface learning to deep learning. Only deep learning can develop students' thinking, the knowledge they have learned is more solid, and students' ability to use knowledge is getting stronger and stronger. On the other hand, if we only master the calculation formulas of cuboids and cubes, on the surface, students can also do related exercises, but their learning ability has not been really developed.

Based on this, the teaching goal can be determined as follows: through experiments (because it is an online course, you can imagine the simulation experiment process in your mind), and express the meaning of cube and cuboid volume calculation formulas in your own words. The volume of a cuboid is the number of unit of volume it contains. Cut a cuboid into cubes of unit of volume. The number of small cubes is related to the side length (length, width and height) of a cuboid. Cubes with different shapes are composed of small cubes, and the number of cubes used (unit of volume) = length (number) × width (number) × height (number of layers/number) of cuboids.

Instructional design concept;

First, make full use of textbooks. Textbooks are the most basic learning materials for students. It is also the most basic teaching material for teachers. So some people directly equate textbooks with textbooks. In fact, "textbooks" contain far more content than textbooks. Textbooks are only one of the materials taught by teachers, but they are the most important materials. Therefore, no matter what subjects, we should make full use of textbooks and teach students how to use them. In the process of listening to the class, we should mark and take notes in the textbook in time. Read the textbook before you do your homework, and reproduce the knowledge through the textbook. Read the textbook first when reviewing.

Second, make full use of the transfer of knowledge. The most important thing in teaching is to know what students already know. This is the starting point of teaching. Let students move from the known to the unknown, which is the process of reviewing the old and learning the new. Confucius said, "Reviewing the past and learning the new can be a teacher." It can be seen how important it is to cultivate students' knowledge transfer ability and use existing knowledge for learning. When students are strong enough, they can "teach themselves" and then they can be teachers of others. In this way, students' autonomous learning ability is cultivated. "Teaching is for not teaching" can become a reality.

Teaching material analysis's explanation:

The calculation formulas of cuboids and cubes to be taught in this lesson are based on the previous lessons. Let's see what the knowledge of the previous lessons has to do with this lesson.

After a preliminary understanding of cuboids and cubes, the textbook arranged "doing" on page 20. Doing things here is not just doing exercises, but doing it by hand. This is a remarkable feature of primary school students' learning, that is, they can do it and experience it. Students must do it and experience it themselves. This is experiential learning. As we all know, the effect of experiential learning is the best among all learning methods.

Build a slightly larger cube or cuboid with small cubes as needed. In my opinion, the design purpose of these topics is to pave the way for the derivation of cuboid and cube volume calculation formulas.

In the process of building, students clearly construct the relationship between small cubes and slightly larger cubes in their minds. The relationship between small cubes and cuboids. And the relationship between cubes and cuboids. If a small cube is regarded as a cube with units, then it is a unit of volume. When we teach units such as length units and area units, we should make students understand repeatedly that the so-called calculation amount is to calculate the number of units of measurement. Calculating the area is how many area units are included in the calculation. Then calculating the volume of an object is to calculate how many unit volumes it contains.

When students use a small cube to build a slightly larger cube, they should further think about the volume relationship between the two cubes. The formula for calculating the volume of the cube is coming out.

Similarly, when students build a cuboid from a small cube, they can quickly calculate the unit of volume by multiplication, and then the cuboid volume formula will come out. .

Exercise 5, question 8 on page 22, constructs students' knowledge structure in another way, so that students can clearly understand the relationship between small cubes and cuboids from another side. This also paves the way for the derivation of volume calculation formula. Question 13 on page 26. It means the same thing, but it's not a small box anymore. But the cuboid is cut into small cubes. It lays a foundation for exploring the volume of cuboid by cutting method.

In the scene on page 29, the main question is: How do you know the volume of a cuboid?

The boy said, "if only it could be cut into small squares of the same size." So can a small cube of the same size be understood as a unit of volume? How many unit of volume does a cuboid have? Its volume is the same. Our teacher's teaching is to let students read this meaning from textbooks. After reading this meaning in the textbook, you will understand what the boys are talking about.

On the other hand, if you understand this, you can guide students. Because the number of unit of volume contained in a cuboid is its volume, we can use unit of volume to make a cuboid to discuss the calculation law of cuboid volume. So there is the following experiment to explore the relationship between cuboids and small cubes.

Coincidentally. After learning the first book, the textbook is arranged on page 28.

The first question is about what quantities 1 cm,1cm 2 and1cm 3 are used to measure respectively. What's their difference?

This topic is to construct the connection between students' length units, area units and unit of volume, and make "differences" through "connection". Because they are intrinsically related, the so-called "points move into lines, lines move into planes, and planes move into bodies". One-dimensional space is a line, two-dimensional space is a space, and three-dimensional space is a body. A line segment has a length, an area has a size, and a volume occupies a space.

Question 2: The following figure consists of a small cube with a side length of 1cm. What are their volumes?

The design intention of this problem once again strengthens the relationship between the volume of small cubes and cuboids. And their relationship with the volume of objects of various shapes. Regardless of the shape of an object, its volume refers to the number of unit volumes it contains.

Teaching process design:

First, the contact information is known: please open the textbook. Before and after reading: the textbook is arranged with "doing" on page 20, question 8 on page 22, doing on page 28 and situation diagram on page 29. In my own words, talk about the relationship between cuboid volume and small cube. The essence of calculating the volume of a cuboid or cube is to calculate the quantity of what?

Students report to the screen, the teacher can choose to browse, or not to judge first, and after the speech, tell their answers directly for students to compare. If you have different opinions, type the word "different". So that the teacher can understand the learning situation. Explain your expression further. Listen to the students after class. For the convenience of the assistant.

Second, explore the unknown: imagine the virtual experiment process in your mind. If there is a small cube, the learning tool can actually do the experimental process. And make experimental records. See if you can come to the same conclusion as the students in the textbook through experiments. Write the experimental results and conclusions on paper. Teacher's feedback is the same as above.

3. Summary: Please use experiments to explain the volume calculation formula of cuboid or cube.

Fourth, form a conclusion: use letters to express the calculation formula of cuboid or cube volume. And give an example to calculate.

Attachment: Content of teaching materials