Designed as a textbook for undergraduate and postgraduate students of engineering and science, Numerical Methods: For Engineering and Science is an attempt to explain the concepts and principles in such a way that the methods can be applied to any discipline. The book begins with an introduction to the concept of numerical method as an approximation for solving a mathematical problem and the various kinds of errors and conditions associated with such a method. Subsequently, the book provides detailed explanations of numerical methods for linear system of equations, single as well as multiple non-linear equations, approximation of functions, numerical derivatives and integrals, single and multiple ordinary differential equations, boundary value problems, and partial differential equations. The last chapter introduces some advanced topics such as approximation using rational functions, finite element methods, and multi-grid methods, for the students interested in numerical computations. The ingenious use of a popular comic character to introduce various mathematical problems is integrated throughout the book to highlight applications of different numerical methods.