Both instructor and student can use this site in Calculus III in a lecture about the divergence of vector field. Students can ask the owner of the site their questions on one of the topics in the site. There is a (lecture notes) section, but it is under construction at this time. There are solved questions and math problems from various topics in Calculus, Differential Equations, and Linear Algebra. The steps shown are provided in enough detail in order to enhance the learning experience for students who are practicing the calculation of the divergence of a vector field.