This math topic focuses on understanding how to represent the domain and range of functions on a number line. The problems involve converting interval notation into a graphical depiction on a number line. Examples of intervals provided in the questions include both finite and infinite intervals, as well as open and closed intervals. The students are also introduced to visual discernment between different types of intervals as they decide which number line correctly represents the given notation. This topic serves as an introduction to the concepts of domain and range in the broader context of function analysis.