Consider the partial differential equation (PDE) with initial condition and boundary conditions and , , and , where is the thermal diffusivity. This problem represents the transient heat conduction in a slab. This Demonstration obtains the temperature profile for user-set values of the dimensionless time and the thermal diffusivity . The red curve and the dashed blue curve are obtained using Mathematica's built-in function NDSolve and the differential transformation method (DTM), respectively. Here, the DTM gives reasonably good results despite its simplicity.