This book serves as a comprehensive resource that highlights innovative practices and techniques within the realm of approximation methods. The book not only explores the theoretical aspects of approximation but also delves into their practical applications across a range of domains. Features:Discusses the application of wavelets to develop computational schemes for solving mathematical models offering a valuable approach to handle a variety of complex phenomena. Presents an inventory model designed for managing inevitable stock containing deteriorating objects, with a focus on time-dependent requirements and factors such as stationary holding and cost debilitation rates. Explores the numerical solution of two-dimensional, viscous magnetohydrodynamic (MHD) flow along a constant wedge through a porous medium. Showcases a stability analysis of thermal convection in a Jeffrey ferromagnetic fluid, focusing on both linear and weakly nonlinear aspects. Highlights an innovative mathematical modeling approach to address sustainability concerns in mixing problems, specifically considering the integration of renewable energy sources. The text is primarily written for senior undergraduates, graduate students, and academic researchers in the fields including electrical engineering, electronics and communications engineering, computer science and engineering, manufacturing engineering, and industrial and production engineering.