Explicit, implicitImplicit, andCrank-Nicolson Crank-Nicolson methods of discretisation of the transient one-dimensional heat transfer equation are described using the finite difference and finite volume approaches. The main attraction of the explicitExplicit method is that it leads to explicit expressions for temperatures at all points in space at the following time instant if the values of this temperature at all points in space at the current time instant are known. This method, however, can be used only for very short time steps and this limits its applicability. ImplicitImplicit andCrank-Nicolson Crank-Nicolson methods lead to a system of equations for temperatures at all points in space at the following time instant, assuming that the corresponding temperatures at the current time instant are known. The number of equations in this system matches the number of unknown values of temperature. The explicitExplicit method is applied to a problem of bondingBonding of two plastic sheetsPlastic sheets heated by an external press. This bondingBonding is achieved when the temperature of adhesiveAdhesive between two sheets reaches a required value. The time required for reaching this temperature, predicted by the explicitExplicit method, is shown to be close to the one inferred from the analytical solution to this equation.