The present Revised edition of the book has been written strictly according to the latest syllabus prescribed by the NCERT. Keeping in mind the mental level of a child, every effort has been made to introduce new concepts in a simple language, so that the child understands them easily. Basic concepts have been explained through attractive illustrations relating to our day-to-day life experiences. The book is divided into 25 chapters. The text is written in a lucid and easy to understand language. The difficulty level of the problems has been reduced and mathematical concepts have been explained in the simplest possible way. Each chapter contains a large number of illustrative examples to understand the applications of concepts. In each section, illustrative examples are followed by an exercise containing an adequate number of unsolved problems. The level of the problems in exercises has been kept such as to encourage the student to practice, so that the student becomes more confident in solving them.