[Teaching objectives]

1, in the estimation activity, experience the function of estimation in real life and experience the estimation method.

2. In the estimation activities, feel the significance of large numbers and develop students' sense of numbers.

3. Deepen the understanding of counting units through counting activities.

[teaching material analysis]

The teaching content of this lesson is the last practical activity of this unit-estimating and counting the number of words. In the second grade, the students have estimated some simple things, such as how many sticks they have caught and the length of the object.

This lesson requires students to estimate how many words there are first, and then make specific statistics. It is still difficult for sophomores to estimate such a large number of things, so I sorted out some materials that need to be estimated in real life and designed them according to the slope from easy to difficult, so as to guide students to gradually understand the estimation methods and make them realize the wide application of estimation in real life.