All Mathemafia YouTube videos of Class 9 chapter 1 (Number System) are embedded on this webpage. You can watch all these videos right here in the same order as they appear in the NCERT textbook. Number system is the base of Mathematics and it is very important for students to have very good knowledge of it. In the first introductory video, Number System has been explained in detail with very easy to understand examples. you are advised to must watch the introductory video before watching any of the chapter’s example or question. Here is the list of all solved video tutorials of this chapter at one place – Examples, concepts, exercises, theorems | Class 9 Chapter 1, Number System.