Reliable numerical solutions to various types of plate structures are of great interest in the field of engineering, since the analytical approaches are limited to homogeneous plates of relatively simple geometry, loading and boundary conditions. The ordinary finite difference method being a numerical method provides approximate solutions to plate problems. Several researches conducted on the ordinary finite difference method, indicated that the method is not well suited for solutions of very large plate systems involving hundreds or thousands of equations. Also, the method is not recommended when higher than fourth derivatives or smaller mesh widths are required. Hence, the improved finite difference method is meant to improve on the deficiencies of ordinary finite difference method in the analyses of rectangular thin plates. This book provides a step by step approach needed in the deflection analyses of the thin rectangular plate using the improved finite difference method (IFDM).