1. 1 knowledge and skills:

Make students know the cuboid, master its characteristics, and learn to read three-dimensional graphics initially.

1.2 process and method:

Let the students know and understand the length, width and height of a cuboid.

1.3 Emotional attitudes and values:

By guiding students to observe and operate, students' exploration consciousness and practical ability are cultivated, and students' initial spatial concept and imagination ability are cultivated.

Emphasis and difficulty in teaching

2. 1 teaching focus:

Master the characteristics of cuboids and know their length, width and height.

2.2 Teaching difficulties:

Initial establishment? Three-dimensional graphics Concept, form appearance.

teaching tool

Multimedia courseware, cuboid model, cuboid-shaped paper box, cuboid-shaped articles with cuboid frame, learning tools such as sticks and balls, and cuboid paper boxes made of learning tools.

teaching process

First, stimulate the introduction of interest

Show some pictures, understand the objects around you, and introduce the learning of cuboids.

1, Teacher: What's the picture on the screen? (Rectangular) Now, please look carefully and see what you find. The courseware demonstrates the process of six rectangles forming a cuboid. )

2. Teacher: The first-year students have already known the cuboid. Can six arbitrary rectangles form a cuboid like this? In this lesson, we will continue to learn some knowledge related to cuboids together.

(Title on the blackboard: Understanding of Cuboid)

3. Teacher: There are many cuboid objects around. Look for them from the theme map. (The computer abstracts the figure of a cuboid)

Teacher: What rectangular things did you bring?

Second, explore new knowledge.

(1) Understand the faces, edges and vertices of a cuboid as a whole.

1, please take out your own rectangular objects and touch them with your hands.

The teacher introduced that the plane part of a cuboid is called the face of a cuboid.

2. The teacher pointed and said: The intersection of two faces of a cuboid is called the edge of the cuboid. Please find the edges of the cuboid.

3. Guide students to observe: the intersection of three sides of a cuboid is called the vertex. Touch it with your hand

4. Teacher: Tell me what you know. Students demonstrate the face, edge and vertex of a cuboid with courseware while talking. )

(2) Explore the characteristics of cuboids

1, independent observation, group cooperation to explore the characteristics of cuboids.

Teacher: Just now, we already know the faces, edges and vertices of a cuboid. Now, please take out the cuboid and carefully observe its face, edges and vertices to see what you find. (Courseware demonstration)

Discuss in groups, and then fill in the table of the math book with your findings.

Tip: When counting the numbers of faces, edges and vertices, students should not turn the cuboid back and forth with their hands. They should figure out how to count, and they should not be repeated or omitted. (Teachers patrol to guide students to observe)

2. Report the communication and summarize the characteristics of cuboids. (Courseware shows questions and answers step by step)

Please note when reporting communication:

(1) Guide students to count the numbers of faces, edges and vertices in a certain order.

When calculating the number of edges, if students don't understand relative edges, teachers should guide students to know relative edges.

(2) After the students introduce the features of cuboid faces and edges, the teachers demonstrate with courseware to deepen their understanding.

(3) Ask students to point out which faces are the same and which sides are the same length in a special cuboid.

3. Take out the learning tools and talk about the characteristics of the cuboid completely according to the questions in the table.

4. Teacher's summary: Through the observation and exploration just now, we know that a cuboid is a three-dimensional figure surrounded by six rectangles. In special cases, two opposite faces are squares. In a cuboid, the opposite faces are exactly the same, and the opposite sides are equal in length.

5. practice.

Please judge right or wrong.

A (1) cuboid has 6 faces, 12 sides and 8 vertices. ( ? )

(2) Four objects with equal length on opposite sides must be cuboids. ( ? )

(3) The lengths of three sides of a cuboid intersecting at the same vertex are equal. ( ? )

(3) Know the length, width and height of a cuboid.

1, hands-on operation, deepen understanding.

(1) Take out your school tools and put them in a rectangular box. What sticks do you want to use and how to insert them quickly? You can work together at the same table or do it yourself.

(2) Teacher: How many groups can the 12 edges of a cuboid be divided into? What is the length of each group of sides?

12 sides can be divided into 6 groups, and the opposite sides are equal in length.

2. Know the length, width and height.

(1) Teacher: I want to know how long metal wire is needed to make this rectangular frame (display teaching aid) and how many sides need to be measured. Why?

Teacher: Are the three sides intersecting at the same vertex equal in length? How to find the total side length?

(2) Teacher: The lengths of three sides that intersect at the same vertex like this are called the length, width and height of a cuboid.

Know the length, width and height of the cuboid in three-dimensional graphics.

3. Know the length, width and height of cuboids placed in different positions.

Put the rectangular box horizontally, vertically and horizontally, and let the students point out its length, width and height respectively.

Third, consolidate and upgrade.

1, deepen the understanding of length, width and height.

Take out your own cuboid, position it, and measure its length, width and height. (Write it on the blackboard after the report)

Summary: The lengths of three sides intersecting at the same vertex can be called the length, width and height of a cuboid, so each person's length, width and height are different due to different cuboid positions, but the sum of length, width and height remains the same.

2. Fill in the blanks and answer.

(1) This rectangle is (8) cm long, (5) cm wide and (5) cm high.

(2) This cuboid with a side length of 5cm has (8) sides.

(3) What shape is the right side of this cuboid? Which side is the same as it?

The right side of a cuboid is a square and the left side is also a square.

(4) What shape is the front? What faces are there like it?

The front is a rectangle, and the same surface as it has a back, an upper surface and a lower surface.

3. Judges.

A (1) cuboid has 6 faces, 12 sides and 8 vertices. ( ? )

(2) The two opposite faces of a cuboid are equal in size and shape. ( ? )

(3) In a cuboid, not all the opposite sides are unequal in length. ( ? )

Summary after class

What new knowledge do you have about cuboids through the study of this lesson?

A cuboid has six faces, each of which is a rectangle (in special cases, two opposite faces are squares), and the shapes and sizes of the opposite faces are exactly the same.

Write on the blackboard.

Understanding of cuboids

Understanding the teaching plan of cuboid and cube (2) Teaching objectives

1. Through observation, operation and other activities, we can know the cube and master its characteristics.

2. Explore the connections and differences between cuboids and cubes through group cooperative learning.

3. Cultivate operational ability and cooperation awareness through learning activities, and develop the concept of space.

Emphasis and difficulty in teaching

The key point of learning is to master the characteristics of cubes and clarify the relationship between cuboids and cubes.

Learning difficulties to establish the concept and formal representation of three-dimensional graphics.

teaching tool

Preparation of cube model learning tool for PPT courseware: several small cubes in cube carton

teaching process

First, review the introduction and introduce new lessons. 6 minutes)

1. Show the cuboid in the courseware and let the students describe its characteristics in words.

2. Look at the picture and tell how many centimeters the cuboid is in length, width and height.

3. Guide students to imagine introducing new lessons.

What will this cuboid become when its length, width and height are equal?

A three-dimensional figure surrounded by six identical squares like this is a cube. In this lesson, we will study and study cubes.

Second, using the transfer of old knowledge, summarize the characteristics of the cube. (13 minutes)

1. Guide the students to recall what they learned about the characteristics of cuboids in the last lesson. (blackboard writing: face, edge, vertex)

Example 3 is given in the courseware.

2. Organize students to try to explore the characteristics of cubes independently according to cubes.

3. Summarize the characteristics of the cube.

Third, observe and discuss the connection and difference between cuboid and cube. (10 minutes)

1. Guide the students to discuss: What are the similarities and differences between cuboids and cubes? Instruct students to fill in the record form. (Teachers' patrol guidance)

2. Discuss the relationship between cuboids and cubes.

3. Try to express the relationship between cuboid and cube with set diagram.

learning plan

1. Recall the knowledge learned in the last lesson, and then report the characteristics of the cuboid from three aspects: face, edge and vertex.

2. Take out the prepared cubic paper box and observe and discuss the characteristics of the cube purposefully from three aspects: face, edge and vertex. Record your findings.

3. Choose a representative in the group to report the observation and discussion results, and the whole class will summarize the report.

Faces: 6 (all square), each face is exactly the same and the area is equal.

Side: 12, each side has the same length.

Vertex: 8.

1. Compare the cuboid model with the cube model, distinguish it from three aspects: face, edge and vertex, exchange your ideas in the group and fill in the record sheet.

2. Through discussion, it is concluded that the cube is a special cuboid.

3. Hands-on operation after communication and display the results.

Fourth, consolidate and improve. (8 minutes)

1. Finish page 20 of the textbook? Do it. .

2. Complete question 6 on page 2 1 of the textbook.

Fifth, class summary. (3 minutes)

1. What did you learn from this class today?

2. Assign homework.

Summary after class

The teaching of this lesson is based on students' learning about cuboids. This lesson is based on the fact that students have the ability to summarize the characteristics of cuboids. When exploring the characteristics of cubes, students should pay attention to their independent exploration and induction. Let the students pass in group activities and practical operations. Look, touch, measure, count and compare? Enrich the perception of cubes, form representations, master the basic characteristics of cubes and other activities, so as to develop students' spatial concepts.

The teaching features of this class are as follows: 1. After reviewing the characteristics of cuboids, let students transfer the method of learning cuboids to the characteristics of cubes, so that students can master the characteristics of cubes quickly and well. 2. Combining conjecture with exploration practice can not only stimulate students' exploration spirit, but also enable them to enjoy the successful experience of conjecture and give full play to their creativity. What is the connection and difference between a cuboid and a cube? The problem will be solved.

homework

1. Fill it in.

A (1) cuboid has () faces, which are generally () shaped, and there may be () faces that are square.

(2) The areas of the top, bottom, front, back, left and right sides of a cuboid are () respectively.

(3) A cuboid has 12 edges, and each edge () is a group, and 12 edges can be divided into () groups.

Answer: (1)6 rectangle 2

Equality 4 3

2. Fill it in.

The (1) cube is a three-dimensional figure surrounded by six ().

(2) Because the cube is a cuboid whose length, width and height are all (), it is a cuboid of ().

(3) The side length of a cube is 2.5cm, and the sum of its side lengths is ().

(4) Weld a 24cm-long iron wire into the largest cubic frame, and each side of this frame is ().

Answer: (1) Square (2) Isometric (3)30cm(4)2cm.

3. In a cuboid, at most () faces are squares.

Answer: 2

Solve the problem.

The side length of (1) cube is 8 cm. What is the sum of its sides?

(2) Enclose a cuboid with a 48 cm long iron wire. This rectangle is 5 cm long and 4 cm wide. What is its height?

Answer: (1)8? 12=96 (cm)

(2)48? 4-5-4=3 cm

Write on the blackboard.

Understanding of Cuboid and Cube (2)

A (1) cube is a three-dimensional figure surrounded by six identical squares.

(2) The cube has 12 sides, and the lengths of 12 sides are all equal.

(3) A cube has eight vertices.