This lesson is the first lesson in this unit. The content of this unit is the understanding of the number within 100 million, including the understanding of the number within 100 million, the reading and writing of the number within 100 million, the rewriting of large numbers and the understanding of the divisor. The concept of number is the basis for students to learn mathematics. Students have learned "Cognition of Numbers within 100" and "Cognition of Numbers within 10000", and the range of cognition of numbers will be expanded to 1 100 million this semester. At this stage, students will know more about natural numbers. It is not only the basis of large number calculation, but also widely used in daily life. Students must learn it well. Laying a good foundation for students at this stage is of great significance for further learning mathematics.

Analysis of learning situation

Knowing larger numbers is the last stage of integer cognition. In the first phase, students have learned the understanding of numbers within 100 and 10000.

Through the first study of logarithm, students have initially realized the numerical system, that is, the same number represents different values with different digits. We also have a preliminary understanding that we use the decimal counting method of all decimal ones. These thoughts are touched by students' understanding of numbers within ten thousand. Students are guided to migrate here to further strengthen the summary.

The most difficult thing for students in this unit is to feel the practical significance of large numbers. Because it is not as clear, definite and tangible as counting in10,20 or 100. Therefore, if we just teach knowledge points blindly in teaching, the motivation is obviously insufficient and we are not interested in boring numbers. Therefore, it is necessary to make full use of intuitive materials and specific situations to stimulate students' interest in learning, which not only conforms to students' curious and active nature, but also makes the old and new knowledge skillfully connect.

Teaching objectives

1. Through the activities of "counting a number" and "dialing a number", I feel the necessity of learning large numbers and realize the practical significance of large numbers.

2. Understand the large-scale counting units such as "1 00000", "million", "1000000" and "1100 million", and understand the relationship between various units.

The focus and difficulty of teaching is to feel the necessity and practical significance of learning large numbers through the activities of "counting a number" and "dialing a number" The difficulty of teaching is to let students establish a sense of numbers through various methods.