Exceptionally great. This book is a treasure that gives you the marvelous ideas about one of the most common and yet important things in the world, the concept of the “Change”. Calculus is study of every aspect of the change. Newton started it and after him so many prominent mathematicians had given their contribution to evolve this beautiful field. Thomas is well versed in every part of the calculus and starts the book with some prerequisites like algebra, trigonometry, geometry and some other parts of college mathematics. Then he continues with Limits which is the corner stone of the rest of the book. After limits he explains thoroughly the concept of derivatives and their applications. And after that you will see integrals which is the most important prerequisite for probability and statistics. After integrals the second part of the book begins with differential equations and infinite series (some people find it a little challenging) and after that is Multi-variable calculus. Multi-variable differentiation is by far the most difficult part of the book especially the chapters about gradients and Lagrange multipliers, but multi-variable integrals is relatively easy to learn. In summary, it was a really enjoyable book to read. If you want to study probability, physics, programming or any other field of study that is pertinent to the concept of the change, you have no choice except learning calculus.