(1) Understand the concepts of sets and elements, and know the three characteristics of elements in sets; (2) Understand the relationship between elements and sets. (3) Master the commonly used number sets and their representations; Teaching emphasis: master the basic concept of set; Teaching difficulties: the relationship between elements and sets; Teaching process: First, introduce the topic.

Before military training, the school informed: At 8: 00 on August 15, the first year of high school will gather in the gymnasium for military training mobilization; Is this notice addressed to all senior one students or to individual students?

Here, set is a common word, and we are interested in the whole of some specific objects in the problem (not individual objects). To this end, we will learn a new concept-set (announcement theme), which is the sum of some research objects.

Read the contents of P2-P3 textbooks.

Second, the new curriculum teaching

(A) the related concepts of set

1. Cantor, the founder of set theory, called a set the sum of some different things. People can recognize these things and judge whether a given thing belongs to this whole. Generally speaking, we call the research object an element, and the whole composed of some elements is called a set.

(set), also referred to as set.

3. Thinking 1: judge whether all the following elements constitute a set and explain the reasons:

(1) is an even number greater than 3 and less than 1 1; (2) Small rivers in China; (3) Non-negative odd numbers;

(4) the solution of equation x2 10;

(5) freshmen of 2007 in a school; (6) patients with hypertension; (7) a famous mathematician;

(8) All points in the third quadrant in the plane rectangular coordinate system (9) Students with good grades in the whole class.

Discuss and comment on the students' answers, and then explain the following questions.

4. On the characteristics of set elements

(1) Determinism: Let A be a given set, X be a specific object or an element of A,

Or an element that is not, there must be one and only one of these two situations. (2) Reciprocity: The elements in a given set refer to different individuals (objects) belonging to this set.

Therefore, the same element should not appear repeatedly in the same collection.

(3) Disorder: A given set has nothing to do with the order of elements in the set. (4) Set equality: the elements that make up the two sets are exactly the same. 5. The relationship between elements and sets;

(1) If A is an element of the set A, it is said that A belongs to (belongs to) A, and it is marked as A ∈ A

(2) If A is not an element of set A, it is said that A does not belong to (does not belong to) A, and it is recorded as aA. For example, if we A represents the set of "all prime numbers in 1~20", there is 3∈A 4A, and so on.

6. Alphabetical representation of sets and elements: Sets are usually represented by capitalized Latin letters A, B and C, and elements of sets are represented by

Lowercase Latin letters a, b, c, indicating. 7. Commonly used number sets and symbols:

Non-negative integer set (or natural number set), recorded as n; A set of positive integers, denoted as N* or n+; Integer set, denoted as z; Set of rational numbers, recorded as q; Set of real numbers, denoted as r;

(2) Give an example:

Example 1. Fill in the blanks with "∈" or ""symbols: (1); (2); (3)Z；

(5) Let A be a collection of all Asian countries, then China A, the United States, Indian A,

British a. Example 2. It is known that the elements of set P are 1, m, m23m3. If 3∈P and-1P are realistic values from the number m.

(3) Classroom exercises:

Exercises in textbook P51;

Summarize:

This lesson begins with examples, naturally and aptly introduces the concepts of set and set, explains the concept of set with examples, and then introduces common sets and their notation.

Task:

1. Exercise 1. 1, question1-2; 2. Preview the representation of the collection. after class