In junior high school, arithmetic is called mathematics, and it is highly abstract, with quantitative descriptions become detailed. Below, the authors will explain a dynamic visualization of the logical development of the contents selected from the range taught in junior high school. Almost all areas of junior high school mathematics are converted into content for dynamic visualization, but here we describe the following eight items as examples. In junior high school, variables are introduced into the representation of number relationships. An equation is then constructed using the variables. The following is a dynamic visualization program aimed at understanding the meaning and usage of variables.