An undergraduate computational project is described. A set of rate equations for a four‐level laser is presented. The steady‐state equations are solved exactly to find nonlasing and lasing solutions and the critical pump rate for the transition between them. The steady‐state solutions are used as a guide to the introduction of suitable dimensionless variables for the rate equations. Illustrative numerical solutions of the rate equations in dimensionless form are presented. The detailed account given of this example is used to bring out a number of points about teaching computational physics.