The book comprises of various numerical methods and their implementation with C-language and MATLAB. Basics of C-programming are covered in first chapter. Basics of errors in computation, number representation and its impact on errors is covered in second chapter. Various types of errors, their propagation, analysis and estimation is also covered in this chapter. Roots of transcendental equations are covered in third chapter. Birge-vieta method, Bairstow method, Bisection method, Secant method, Regula Falsi, Newton Raphson methods are discussed in detail. Fourth chapter focuses mainly on solution of simultaneous linear equations. Graphical, matrix inversion, substitution, Gauss' elimination, Gauss Jordan, LU decomposition, Gauss Seidel methods are discussed with the help of numerical examples. Curve fitting is discussed in fifth chapter. Finite differences operators, finite differences, Newton's forward and backward difference interpolation, divided differences interpolation, Lagrange’s interpolation, inverse interpolation, least squares approximation are presented. Numerical differentiation and integration is given in sixth and seventh chapter. Simpson's and trapezoidal rules of integration are presented. Solution of ordinary differential equations is given in eighth chapter. Taylor series, Picard’s methods, Euler's RK methods, Predictor corrector methods, boundary value problems and eigen value problems are also presented. Last chapter deals with unconstrained and constrained optimization. All the methods are implemented using C-program and some of them with MATLAB. Large number of solved and unsolved examples are also given.