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Teaching material analysis:

This unit is taught on the basis that students have mastered the characteristics of rectangles and squares and the calculation of their perimeters. The teaching materials include the following contents

1, area and area unit. When teaching, we should make full use of intuition and mobilize students' multiple senses to carry out teaching activities. Make students understand the meaning of area and establish the correct representation of common area units (square centimeter, square decimeter and square meter). The textbook also specially arranges the comparison between area units and length units to avoid confusing the calculation of area and perimeter.

2. Calculation of rectangular and square areas. This part of the content is very important, and it is the basis for students to learn other plane graphic product calculation in the future. In the teaching process, teachers should focus on guiding students to operate, find out the relationship between area and side length, and thus sum up the formula for calculating area, so that students can experience the process of knowledge formation.

3. Promotion rate between area units. The teaching materials here include progress and simple conversion between units. Learning these contents well can not only deepen students' impression of the size of each area unit, but also improve students' ability to solve practical problems.

4, hectares, square kilometers. This content mainly introduces the area units in Jiao Da, which are often used to measure the land area, and we sometimes call them "plot units". Understanding these two units is of great help to our future life and productive labor.

Teaching objectives:

1, so that students can understand the meaning of area, establish the correct representation of common area units, master the calculation methods of rectangular and square areas, and be skilled in answering questions, master the progress between area units and make simple calculations.

2, can use the knowledge and skills learned. To solve the problems encountered in real life and improve their abilities.

3. In the process of learning, feel the fun of mathematics, feel that mathematical knowledge comes from life, and feel that mathematical knowledge is applied to life and serves life.

4. Cultivate the spirit of unity and cooperation through learning activities.

Teaching focus:

Understand the meaning of area, establish the correct representation of common area units, and master the calculation of rectangular and square areas.

Teaching difficulties:

The derivation process of rectangular and square area units.

Teaching focus:

Teachers should guide students to operate and observe carefully and find out the relationship between area and side length.

The third category

Area calculation of rectangle and square

Teaching content:

Example 2 on pages 77-78 of the textbook

Teaching objectives:

1. Guide students to find the formula for calculating the rectangular area, so that students can have a preliminary understanding of the calculation method of the rectangular area and use the formula correctly.

2. Guide students to deduce the square area formula by calculating the area of the rectangle.

3. Initially cultivate students' ability to ask, analyze and solve problems.

Teaching focus:

Calculate the area of rectangle and square.

Teaching preparation:

courseware

Teaching process:

First, review the introduction, self-study feedback

Students, we learned about area last class. What are the commonly used area units?

Second, teachers' inspiration and understanding methods

1, cleverly ask questions to stimulate interest

What is the area of our classroom? Students can guess and use area units to measure. The teacher pointed out that it is too troublesome to measure such a large ground with area units, and it is necessary to study how to calculate the area of a rectangle.

2, hands-on operation, research methods

The teacher prepares three different rectangles, and each group chooses only one to study. One kind: a rectangle with a length of 3 cm and a width of 4 cm. Two kinds: rectangles with a length of 4 cm and a width of 2 cm.

Three kinds: rectangles with a length of 5 cm and a width of 3 cm.

(1) Students study in groups and try to find out the area of each figure.

(2) Students report in groups and talk about their own methods. (Possible situation: measure with 1 cm2 or only measure the length and width, and multiply by the area. )

In this process, the teacher gives timely guidance, and the latter method is relatively simple.

(3) communication between teachers and students, refining methods. What does the area of a rectangle have to do with it? Think independently before communicating.

Teacher's instruction: Rectangle is placed in 5 rows, which means 5 cm; It's three lines wide, which means it's three centimeters. So, what is the area of 15 square centimeter? Area of rectangle = length × width. )

(4) Students think: What is the area of a rectangle? Then students think about how to calculate the area of our classroom.

Courseware demonstration: Example 2 Students independently complete and proofread.

Third, the transfer of knowledge.

The teacher took this opportunity to teach square area calculation. We know that a square is a special rectangle with the characteristics of a rectangle, so the area calculation of a square can be the same as that of a rectangle.

Fourth, contact life and solve problems.

1. What is the area of the math book we use? Please estimate first and then calculate. Students complete and report independently on the first network of the new curriculum standard.

2. Finish textbook No.78, and then do it.

3. Complete questions 1, 2, 3 and 4 on page 79 of the textbook.

Verb (abbreviation of verb) abstract

In this lesson, we learned and mastered the formula for calculating the area of rectangle and square. The area of a rectangle is equal to the length times the width, and the area of a square is equal to the side length times the side length. It should be noted that the area unit must be used to calculate the area unit and should not be confused with the length unit.

What did you buy today?

Blackboard design:

Calculation of rectangular and square areas

Area of rectangle = length × width

Area of a square = side length × side length