We discuss the need for devoting time in differential equations courses to modelling and the completion of the modelling process with efforts to estimate the parameters in the models using data. We estimate the parameters present in several differential equation models of chemical reactions of order n, where n = 0, 1, 2, and apply more general parameter estimation approaches to an optimization problem involving the production chemical reaction A [right arrow] B [right arrow] C. (Contains 1 note, 3 tables, and 10 figures.)