In this book, we use of FORTRAN to solve a complete collection of exercises: first algorithms (16 exercises), decision statements and file reading (27 exercises), exercises related to regression line, limits, functions, approximations, remainders, counters and output files (14 exercises), vectors, matrices, determinants and systems of linear equations by Cramer's rule (20 exercises), functions and subroutines (6 exercises), bisection and false position methods (6 exercises), Newton-Raphson and secant methods (6 exercises), systems of linear equations by Gauss method (3 exercises), factorization of a matrix by Doolittle algorithm (1 exercise), direct and Lagrange interpolation methods (2 exercises), Newton and Newton-Gregory interpolation methods (3 exercises), Backward, centered, forward, interpolating polynomial and Richardson methods for numerical derivation (3 exercises), Interpolating polynomial, trapezoidal and Simpson s methods for numerical integration (3 exercises) and explicit and centered Euler and Heun (Runge-Kutta of order 2) methods for differential equations (2 exercises).