International Science Community Association Research Journal of Mathematical and Statestical Sciences 14 3 2026 09 12 A Non-Uniform Haar Wavelet Method for Coupled Problems 4 9 EN Pankratov E.L. 1 Nizhny Novgorod State Agrotechnical University, 97 Gagarin Avenue, Nizhny Novgorod, 603950, Russia Rawan Sunil 1 Department of Mathematics, Balganga Degree College, Sendul, Kemar, Sri Dev Suman Uttarakhand University, Tehri Garhwal, Uttarakhand, India, 249155 > Research Paper 2026 7 26 2026 09 12 In this paper, an approach for the solution of systems of first and second order linear partial singularly perturbed (LPSP) initial and boundary value problems or coupled problems, respectively, has been proposed using non-uniform Haar wavelets in wavelet collocation method. Three different types of meshes have been considered. Maximum absolute residual errors (MAREs) of numerical solutions obtained by proposed method have been presented in tabular form. The numerical results demonstrate that the proposed method yields highly accurate approximations. Copyright@ International Science Community Association