Student of today's are future of India. Therefore, our duty and responsibility to all is to create a decent environment for education. so that it can contribute to the development of the country and promote prosperity. This is an era of computer and information technology. The most striking aspect of technology is that it provides excellent opportunities for education to the students in schools and schools. Students in this era of technology revolution are very essential for students. We are delighted to publish a series of "Friendship with Computer" class 1 to 8 for the purpose of spreading computer literacy. Every book of this series is written in very easy and simple language. Using screen-shots, students have been carefully and easily learn the computer. In addition to this, each subject has been presented logically. This book has been prepared in a manner consistent with the principle of "Education without Burden". The exercise and the practical department are given for the student's self-study and evaluation. This book of Standard-3 provides knowledge-making with beautifully colored images. Through this book, students will be familiar with computer history, input-output devices, key-board usage, calculator and paint program. Your valuable suggestions on this book are welcome.