This note discusses the Black-Scholes option-pricing model and then applies the model to call options. The underlying logic of the model is emphasized and illustrated through the use of simple examples. The model is then applied using real data. The note pays particular attention to procedures for estimating the potential for stock-price changes (volatility). It also provides the reader with an appreciation of the economic underpinnings of the model as well as the ability to apply the model to real data.