The fifth chapter "Location Determination" is the main content of the third issue of "Graphics and Coordinates". "Graph and coordinate" is one of the four important components of "space and graph" (graph cognition, graph and transformation, graph and coordinate, graph and proof), and it is an important carrier for developing students' spatial concept. As the development of the first and second issues of Graphics and Coordinates, this chapter is not only presented at the same time, but also an important basis for the sixth chapter of the book, Linear Function.

Two. The teaching objectives of this chapter are:

1. Knowledge and skill objectives:

(1) There are many methods to determine the position of an object, and different methods can be flexibly used to determine the position of an object;

(2) Understand the concept of rectangular coordinate system, and trace the position of a point or write its coordinates according to its position in a given rectangular coordinate system;

(3) An appropriate rectangular coordinate system can be established on the grid paper to describe the position of the object;

(4) We can know the characteristics of some special point coordinates, and we can calculate the coordinates of some special points according to these characteristics;

(5) In the same coordinate system, feel the change of coordinates of points after the change of graphics and the change of graphics after the change of coordinates.

2. Process and method objectives:

(1) Let the students choose the appropriate method to represent the position of the object by feeling the examples;

(2) Through association and imitation, the method of establishing plane rectangular coordinate system is preliminarily realized;

(3) By drawing, we can understand the graphic changes caused by point coordinate changes.

3. Emotions, attitudes and values:

(1) By constructing a plane rectangular coordinate system, the combination of numbers and shapes in a wider range is formed, so that students can experience that mathematics comes from life and serves life at the same time;

(2) Cultivate students' study habits of observation, analysis, inquiry and cooperation, and experience the changes of things; (3) By discussing the relationship between the change of graphic coordinates and the change of graphic shapes, we can cultivate students' awareness of the combination of numbers and shapes, their thinking ability in images and their mathematical application ability, and form students' good mathematical outlook.

3. Teaching ideas of this chapter:

In this chapter, according to the arrangement of "general" and "special", first let students feel the rich realistic background of location determination through colorful and diverse ways. Then let the students systematically learn the relevant contents of the plane rectangular coordinate system based on very practical background materials; Finally, through the interesting topic of "changing fish", the change of graphic coordinates is skillfully linked with the change of graphic shape.

This chapter attempts to present relevant contents with realistic themes, and presents the content of "finding coordinates from points, determining the position of points by coordinates, and establishing a simple plane rectangular coordinate system" with interesting and challenging questions, trying to reflect the connection between the plane rectangular coordinate system and the real world; Through "changing fish", there are a lot of graphic transformations in real life, such as various picture processing on TV screen. For all kinds of methods to determine the location, this chapter presents common positioning methods in real life to every student through various themes (such as "monsters eat peas", "finding seats in cinemas" and "determining the location of cities on maps"), including positioning methods that reflect polar coordinates and rectangular coordinates.

This way of presentation, first, allows students to understand the coordinate thought and its origin in relatively relaxed and interesting activities, and further develops students' reasonable reasoning ability and rich emotional attitude (especially their interest in learning mathematics); The second is to master the basic methods of determining position and the basic knowledge and methods of plane rectangular coordinate system in a large number of practical applications.