1. Let students know the characteristics of a circle: radius, diameter and center. Understand the relationship between radius and diameter in the same circle. You should know that a circle is an axisymmetric figure with countless symmetry axes, all of which pass through the center of the circle. Knowing that there is a circle in life makes our life better.

2. Know concentric circles and equal circles. You should know that the position of the circle is determined by the center of the circle, and the size of the circle is determined by the radius or diameter. Equal circles have the same radius and different positions; Concentric circles have different radii and the same position.

3. Make students know the meaning of circumference and pi, master the formula for calculating circumference, and calculate circumference correctly. This paper introduces Zu Chongzhi's achievements in the study of pi, and permeates patriotic education. In practice, if the diameter or radius can be calculated according to the circumference of a circle, the circumference of a semi-circle can be calculated: the circumference of a circle × 1/2+ diameter. Find the perimeter of the combined figure.

4. Understand the meaning of the area of a circle, go through the derivation process of the formula for calculating the area of a circle, and master the formula for calculating the area of a circle.

5. Be able to correctly calculate the area of a circle by using the formula of the area of a circle, and solve some simple and practical problems by using the knowledge of the area of a circle. Can flexibly use the area formula of a circle. Given the circumference of a circle, the area of the circle will be calculated, and the area of the combined figure will be calculated. Can calculate the area of a circle and know the areas of squares, rectangles and circles with the same perimeter.

6. In the activities of estimating and exploring the formula of circular area, I realized the idea of "turning a curve into a straight line" and initially felt the limit idea.

Application of the second unit percentage

This unit focuses on the application of percentage in life. The knowledge points are as follows:

1. Know the meaning of percentage: the number indicating that one number is the percentage of another number is called percentage. Percentages are also called percentages or percentages. Percentages are usually not written in the form of fractions, but expressed by percent sign "%"; Percent is sometimes defined as a fraction whose denominator is 100, but there is a difference between percentage and fraction: a fraction can represent a specific quantity or a multiple relationship between two quantities; However, percentage can only represent the multiple relationship between two quantities; So it is an unnamed number, that is, a number that cannot take units.

2. Understand the meaning of "increase by a few percent" or "decrease by a few percent" under specific circumstances, and deepen the understanding of the meaning of percentage.

3, can solve the practical problems about "increase by a few percent" or "decrease by a few percent", improve the ability to solve practical problems by using mathematics, and realize the close relationship between percentage and real life.

4. Knowing the significance of the percentages of attendance, flour yield and survival rate and their application in real life, we will calculate this percentage.

5. Know the meaning of discount. A number that indicates that one number is a few tenths or a few percent of another number is called a number. Discount refers to selling at dozens or one tenth of the original price. 15% discount means selling at 85% of the original price. Fractions and discounts cannot be expressed in decimals.

6. It can solve the practical problem of "how much a number increases" or "how much a number decreases".

7, further strengthen the understanding of the percentage meaning, and can solve practical problems according to the equation of percentage meaning, and can solve the equation containing percentage.

8. Be able to use percentage related knowledge to solve some practical problems related to savings and improve the ability to solve practical problems. Know that interest is the extra money after the principal is deposited in the bank for a period of time; The principal is the money in the bank; Interest rate is the percentage of interest to principal in a certain period; Interest tax is a tax levied on interest income stipulated by the State Bank. Will calculate interest. Interest = principal × interest rate× time

9, combined with savings and other activities, learn to manage money reasonably, and gradually develop a good habit of not spending money indiscriminately.

Unit 3 Graphic Transformation

1. Through observation, operation and imagination, we can know how a simple figure translates or rotates into a complex figure, experience the transformation of the figure and develop the concept of space. With the help of calculation and analysis on grid paper, the transformation process of graphic translation or rotation is expressed in an orderly way.

2. You can use puzzles to transform various graphics on grid paper. Can use the transformation of graphics to design beautiful patterns on square paper, and further understand the role of translation, rotation and axial symmetry in pattern design.

3. Appreciate the patterns and feel the magic of the graphic world. Through the interesting and beautiful patterns in life, we can know the beauty of mathematics and experience the magic of the graphic world.

Understanding of the fourth unit ratio

1, can abstract the process of comparison from specific situations and understand the meaning of comparison.

2, can read and write the ratio correctly, can find the ratio, and understand the relationship between the ratio and division and fraction.

3. Be able to use the knowledge of ratio to explain some simple life problems and feel the widespread existence of ratio in life.

4. To understand the necessity of simplifying the ratio, we can use the invariance of quotient or the basic properties of fraction to simplify the ratio and solve some simple practical problems.

5, can use the meaning of the ratio to solve the practical problem of distribution according to a certain proportion, and improve the ability to solve practical problems.

Expanding ability: the ratio can be simplified by calculating the ratio.

Unit 5 Statistics

1. Know the characteristics of composite bar chart and composite line chart, understand the similarities and differences between simple chart and composite chart, and use composite bar chart and composite line chart to represent the corresponding data on the chart of vertical axis and horizontal axis to realize the function of data.

2, can understand the composite bar chart, and can make simple analysis, judgment and prediction according to the relevant data in the composite bar chart.

3. Data will be collected and classified. And find problems through data analysis, so as to decide what statistical chart to use to describe the data.

Unit 6 Observing Objects

1, which can correctly identify the shape of a three-dimensional figure (the combination of five small cubes) observed from different directions (front, side and top) and draw a sketch.

2. We can restore the three-dimensional figure according to the plane figure observed from the front, side and above, and further realize that the shape of the three-dimensional figure can be determined from three aspects, and the number range of cubes needed to construct this three-dimensional figure can be determined according to the shape of the plane figure observed from two given directions.

3. According to the reality of life, I experienced the process of abstracting the eyes, sight and observation range into points, lines and regions respectively, and felt that the observation range changed with the change of observation points and angles, and I was able to explain some phenomena in my life with what I learned.