Rate of Change in Temperature Project Overview  This RWLO describes a lesson plan that instructs students to solve an instantaneous rate of change word problem using Calculus I skills, calculator skills, online skills, as well as critical thinking skills.  Students will determine in which month the temperature increases most rapidly, decreases most rapidly, and changes most slowly for a major city of their choice in the U.S.A.   Students will begin by breaking into small groups.  Each group will predict the months where the temperature changes most rapidly or most slowly, even though they have no mathematical evidence or knowledge of the actual months.  They will provide some sort of rationale for their predictions.     To find the actual real months, students begin by gathering data from the internet.  They will use a graphing calculator to obtain a regression function and its graph to observe the curve of best fit to the data set.  Students will use their differentiation skills to find the derivative of the regression function.  After graphing the derivative function, students use their knowledge of differentiation and their critical thinking skills to analyze the graph in order to obtain the real results.  Alas, the truth is known!   Finally, students will compare their predictions made in the beginning with the actual real results found through mathematics.  The lesson is completed by giving a reward to those students who predicted all the months accurately.