1. Through comparative experiments, it is found that the speed of the same paper dragonfly is different after adding "tail" or changing "wings".

2. Experience the fun of exploration in exploration activities.

Activities to be prepared

1, some paper dragonflies (red, green, blue and yellow dragonflies account for half of the children, and pink dragonflies have one hand).

2, scissors, plasticine.

3. Children have mastered the rules of comparative experiment.

Activity Focus: Discover the secret of paper dragonflies flying fast.

Activity difficulty: Make paper dragonflies that fly faster.

Activity process

First, know the paper dragonfly

1. Show a paper dragonfly and guide the children to have a look, think about it and say what it looks like.

2. Pointing to the wings of a paper dragonfly, ask: What paper dragonfly is this? How long is it? Pointing to the tail of a paper dragonfly, he asked: What is this?

Second, explore paper dragonflies

Exploration 1: Guide children to make paper dragonflies spin.

1, please choose a paper dragonfly for each child and try to make it spin. Paper dragonflies for children are half red dragonflies with long wings and half green dragonflies with short wings.

Children are free to play, and teachers patrol to observe and guide.

2. Question: How did you make your paper dragonfly spin just now? (Please operate by individual children)

The teacher summed up according to the children's operation: the wings should be balanced, one on the left and the other on the right. Let go gently, and the paper dragonfly will turn itself.

3, children play with paper dragonflies again, after mastering the method, organize children to let all paper dragonflies dance together. (The paper dragonfly is held as high as the line prepared by the teacher and released at the same time)

Exploration 2: the relationship between the length of paper dragonfly wings and turning speed

1, red dragonfly and green dragonfly form a group respectively. The children competed in pairs to see who could spin fast. Teachers' roving observation and guidance.

2. Guide the children to stand on both sides according to the winning or losing results of the competition. Q: What did you find? What color paper dragonfly did you win? (Green) Why do you win all the green dragonflies? The "wings" of the green dragonfly are very short and turn down quickly; The "wings" of the red dragonfly are very long.

Exploration 3: the relationship between the weight of paper dragonfly tail and turning speed

1, blue dragonfly and yellow dragonfly each form a group. Let's compare and see which one turns faster.

The paper dragonfly for children is half blue dragonfly and half yellow dragonfly. The wings of the two paper dragonflies are the same length, but plasticine is added to the tail of the blue dragonfly to make the tail heavier.

2. Children should stand up again according to the results of winning or losing the competition. Q: What did you find? What color paper dragonfly did you win? (Blue) The wings of two paper dragonflies are the same length. Why did they win the blue dragonfly?

3. Guide children to touch the tail of the blue dragonfly, and then reveal what is hidden in the tail of the blue dragonfly-plasticine. The blue dragonfly's tail rotates fast when it is heavy, and the yellow dragonfly's tail rotates slowly when it is light.

Exploration 4: The secret of paper dragonflies spinning faster.

1. Give each child a pink dragonfly and encourage them to turn it into a paper dragonfly faster than red dragonfly, yellow dragonfly, blue dragonfly and green dragonfly.

2, children explore the operation, teachers patrol observation and guidance.

3. Question: How did you turn pink dragonfly into the fastest?

Summary: If the paper dragonfly has short wings and heavy tail, it can turn faster.