Page 6, Unit 1, Volume 5, Beijing Six-year Textbook.

Teaching purpose:

1. Through physical demonstration and students' hands-on operation, students can initially establish the concept of multiple, and get ready for learning the application problems of multiple relationship.

2. Cultivate students' observation ability, hands-on operation ability and language expression ability.

3. Enlighten students with dialectical materialism.

Teaching emphases and difficulties:

Establish a pluralistic concept.

Teaching aid preparation:

The teacher prepares butterfly pictures, disks, triangles and zoo maps; Students prepare inkpad, rubber stamp engraved with red flowers and paper.

Teaching process:

1. Introduce new courses

There is a beautiful big flower bed on campus. Colorful flowers are blooming in the flower bed, attracting many butterflies. (Show pictures of butterflies)

How many white butterflies are there? How many Hua Hu Die are there?

How many more butterflies are there in Hua Hudie than in White Butterfly?

How else can I say this sentence?

The answers are all right. However, compared with White Butterfly, flowers have a new relationship-multiple relationship besides phase difference. Learn twice as much today. (blackboard writing: times)

2. Establish a pluralistic concept

(l) Building concepts:

(1) conversation:

I regard two white butterflies as one. (blackboard writing 1 circle, circle 2 white butterflies)

How many twos does Hua have? (Draw three circles on the blackboard, and Hu Die draws a circle every two flowers.)

Compared with the white butterfly, the flower has two white butterflies and two blackboard books.

China has three Liang. (3 blackboard books, 2. )

When the number of white butterflies in flowers reaches three, we say that the number of white butterflies in flowers is three times. There are only three times as many books on the blackboard as there are now.

② Discussion:

The number of flowers is only several times that of white butterflies.

How do you know that there are only three times as many flowers as white butterflies?

Because there are two white butterflies in flowers and three in flowers, the number of white butterflies in flowers is three times that of white butterflies.

(2) Variants:

(1) there are two Hua Fei came in, and now the number of China is several times that of the white butterfly. Why?

② Another 1 white butterfly and 1 flower flew in. How many times does Hua have now? Why?

(3) Summary:

To answer that the number of flowers is only several times that of white butterflies, we should first look at how many white butterflies there are, and then look at how many white butterflies there are and how many times there are flowers.

3. The concept of integration time

(1) Group exercise:

①

_

What is the number of delta? Why?

② Teacher's Pendulum _

The number of △ is twice that of ○. Who can reverse it?

③ Green circle: _

Red circle: _

Blue circle: ○ ○.

The green circle, red circle and blue circle on the left are compared with the increment on the right. Who can tell the relationship of multiples?

(2) Hands-on exercises for each person:

Young pioneers did a lot of good things by learning from Lei Feng. The squadron Committee decided that every good thing that everyone did would be awarded a small red flower. Would you please help cover the little red flower?

① The first row is covered with four red flowers, and the second row is covered with two four flowers.

How many flowers are covered in the second row?

How many times are there more flowers in the second row than in the first row?

The first row is covered with two red flowers.

One or two sets of covers: the number of flowers in the second row is five times that in the first row.

Three or four groups of covers: the number of flowers in the second row is four times that in the first row.

Five or six groups of covers: the number of flowers in the second row is three times that in the first row.

Seven or eight groups of covers: the number of flowers in the second row is twice that in the first row.

After the students cover it, each group answers: How many 2 flowers were covered in the second row? How many times are there more flowers in the second row than in the first row?

③ How many flowers can be covered in the first row, but the number of flowers in the second row must be twice as many as that in the first row.

After reading it, the students will ask:

How many flowers are there in the first row? How many flowers are there in the second row? How many different answers? )

The number of flowers covered by each student is different. Why are there twice as many flowers in the second row as in the first row?

(3) Clap game:

① How many times does the teacher clap? (3 times) How many times did you eat for the second time? 3 times? How many shots were fired the second time?

(2) Teachers and students shoot:

(After the teacher took two pictures) You took four times as many pictures as the teacher did.

(After the teacher's hand 1) Your hand is five times that of the teacher.

(3) deskmate:

Note: the first shot must be within 5, and the second shot is twice as much as his.

4. Prepare for learning multiple relationship application problems.

Do you like going to the zoo? Will the teacher take you to the zoo? Show me the map of the zoo. )

Take a look at the animals in the zoo. How many are there in each animal?

See who can say a few words about the multiple relationship.

Students discuss and the teacher writes on the blackboard:

There are only five times as many birds as pandas.

Five two two.

There are only twice as many monkeys as squirrels.

Two, three, three.

There are only four times as many rabbits as elephants.

4 1 1

(2) After seeing or hearing who is who several times, we should think of three points:

(1) who and who than.

(2) Who is the standard and who is regarded as 1.

③ 1 has several copies, which is several times that of 1.

summary

In this lesson, we have a preliminary understanding of time. Complete writing board: double understanding. )

Understand the meaning of this sentence, and it will be easy to learn the application problems of multiple relationships in the future.

6. Homework Write two sentences with multiple relationships and tell the meaning of each sentence.