The third lesson (pages 69 and 70) of Unit 5 "Observing Objects", the standard experimental textbook of compulsory education curriculum of People's Education Press (the first volume of grade two).

Teaching objectives

1. Understand the characteristics of mirror symmetry graphics.

2. Through student activities, correctly understand the relativity of mirror symmetry.

3. Cultivate students' sense of cooperation, and let students communicate, learn and interact in cooperation.

Emphasis and difficulty in teaching

Experience the relativity of mirror symmetry.

Prepare teaching and learning tools

Textbook 7 1 page mirror, open questions, cards.

teaching process

First, play with the mirror and create a situation.

1. Children, let's play with the mirror in class today, shall we? Everyone has a small mirror.

Teacher: What do you see in the mirror?

Health: I saw myself; I saw this book; I see the blackboard.

Teacher: What's this?

Second, guide exploration and experience the characteristics of mirror symmetry.

1. Show the theme map on page 69 of the textbook for students to observe carefully.

(1) Teacher: Why are there two houses and six swans in this painting? Why are there trees on the shore and underwater?

(2) Health: The houses, swans and trees below are all shadows in the water.

Teacher: (Enlarge the picture of the house) Is the house on the water the same as the house under the water? What is their direction?

Health: It looks the same, but in the opposite direction.

Teacher: Actually, this is also mathematical knowledge, which is a kind of mirror symmetry. (Show the topic)

2. Let the students play games with mirrors.

(1) Give the students a card with only half of the image, and let them try to guess what the other half of the image is. (Group activities)

Group report: look in the mirror; Fold the card in half. ...

(2) Look at your face in the mirror and make various facial expressions, and observe the changes of your facial expressions in the mirror.

(3) Show the picture of the child looking in the mirror on page 69 of the textbook (Example 3)

Teacher: What is the child doing? What are the children doing in the mirror?

The teacher said, "Children, shall we look in the mirror?" Show three mirrors and let the students do various actions in front of them. At the same time, ask students to tell what their actions are like in front of the mirror. Group activities in which teachers participate. )

Health: I walk forward, I walk forward in front of the mirror.

In the mirror, I have a pen in my left hand and a notebook in my right. Outside the mirror, I have a notebook in my left hand and a pen in my right.

I go left, I go right in the mirror.

Students do actions at will. ...

Third, use expansion.

1. Judge. What you see in the mirror. Circle it. (textbook page 765438 +0, question 5)

2. Find friends.

3. Thinking about problems: Questions on page 7 1/and 2.

(1) Write in the mirror

(2) Look in the mirror and write down the time.

Fourth, summarize and evaluate.

Teacher: Look, look in the mirror, reflect on the water, and so on. All these things in life are mathematical knowledge, you know?