This video covers categorization of numbers into different names such as Real Numbers, Rational Numbers, Irrational numbers, Integers, Whole Numbers and Natural Numbers. This video covers parts of Section 1.1 and Section 1.2 of NCERT Class IX Math book. The book is available free of cost at the following link: www.ncert.nic.in/ncerts/textbook/textbook.htm Please ask questions, if any, through comments on this video. I'll be happy to respond :) Also, please share your feedback as to what you liked about the video and how can I improve these videos.