The method of judging which number a number is closer to can be simplified by the number it is close to. The smaller the difference, the closer it is.

Mathematical concept is the reflection of the quantitative relationship and the essential attribute of spatial form in objective reality in the human brain. The research object of mathematics is the quantitative relationship and spatial form of objective things. In mathematics, the color, material, smell and other attributes of objective things are regarded as non-essential attributes and discarded, and only the same attributes in shape, size, position and quantity are retained.