Glioblastoma multiforme (GBM), a highly lethal brain cancer, accounts for over 30 percent of brain tumors in adult patients. Patients typically survive only 12-18 months after diagnosis. Our model describes the dynamics of GBM via a system of partial differential equations for tumor cells, nutrients, toxins, and mechanical resistance of brain matter. Using a 2D conservative Alternating Direction Implicit scheme, we numerically approximate the solution to our model and implement it in C for simulation on a parallel computer.