Day by day Digital world is expanding with a very high speed. New technologies and application software are emerging day by day, creating a completely new pace and atmosphere in the field of Office Environment is must. The new concepts and the terminologies in the field of Computer Science are expanding very fast, yet the data representation basic concepts in computers are very necessary for every student of computer science. Everyone should put efforts to properly understand the heights of the developments of the technological world and implement them in proper field. In this book, the basics of Data representation and computer arithmetic presented in such a manner so that a beginner can find this book fully tailored to his/her requirements and the one who is already in this field will find it more informative for quick reference. The book presents each and every concept in a very simple language and easy to understand with the help of relevant illustrated examples. The book provides the complete concepts of Data representation and arithmetic in computers . The book will prevent students to get boggled in the market and spend money on different books on different topics.