Laplace's equation: Five- point formula , diagonal five point formula, Jacobi's method, gauss- sedial method and successive over relaxation methods. Parabolic equation in one space dimension. Two levels and three levels difference method - Schmidt method. Laasonen method, Crank Nicolson method, Dufort and Frankel Method. Hyperbolic equation in one space dimension. Explicit three level difference scheme, Implicit scheme, First order hyperbolic equation Lax- Wendroff formula.