There are about 300 grams of primary school math books and about 600 grams of middle school math books.

Gram, the unit of mass, symbol G. One gram is the mass of18×140744812 atoms, and the weight of one gram is about the weight of one cubic centimeter of water at room temperature.

Ways to learn mathematics well:

1. To learn mathematics well, we must grasp three "basics": the basic concepts should be clear, the basic laws should be familiar, and the basic methods should be skilled.

You must sum up the topic carefully after you finish it, so that you won't spend too much time and energy when you encounter similar problems in the future.

3, we must fully understand the mathematical concepts, don't generalize. The ultimate goal of learning concepts is to solve specific problems with concepts. Therefore, we should actively use the mathematical concepts we have learned to analyze and solve related mathematical problems.

4, to master the problem-solving methods of various types of questions, consciously sum up in practice, and slowly cultivate the analytical habits that suit you.

5, to actively improve the ability of comprehensive analysis of problems, with the help of text reading for analysis and understanding. In learning, we should consciously pay attention to the transfer of knowledge and cultivate the ability to solve problems.

6. We can integrate the knowledge we have learned into a system by analogy. Linking the contents of each chapter with each other, comparing different chapters with each other and truly integrating the knowledge before and after can help us understand the knowledge system and content systematically and deeply.

7. In mathematics learning, we can compare similar concepts or laws with formulas to find out their similarities and differences and connections, thus deepening our understanding and memory. Clear the relationship between mathematical knowledge, thoroughly understand the concept, know its derivation process, so that knowledge is organized and systematic.