“…In this case, the preliminary work has been done by Balasim and Ali (2016-17) [10][11][12] on two-dimensional timefractional diffusion and advection-diffusion PDEs, by utilizing Caputo's fractional derivative, where the time-fractional derivative of order α lies between 0 and 1. In addition, the most recent work by Ali and Ali (2018-19) [3][4][5] on two-dimensional time-fractional wave, damped wave and hyperbolic telegraph PDEs, by using the same definition of Caputo's fractional derivative, where the order of time-fractional derivative α ∈ (1, 2). In this paper, we step forward towards the numerical solution of more complicated 2D timefractional anomalous sub-diffusion equation by applying by Riemann-Liouville fractional derivative and grouping methods, and results were found according to our expectation.…”