The meaning and nature of decimals is the content of Unit 4 in the second volume of Grade Four Mathematics. The knowledge points of this unit are complex and have a lot of contents, among which the most difficult is the movement of decimal point.

The unit of meaning and nature of decimals is divided into five sections, which are the meaning and reading and writing methods of decimals, the comparison of decimal nature and size, the change of decimal size caused by decimal movement, decimal unit and conversion, and the approximate number of decimals.