But calculus (or analysis) is also very technical. It takes a lot of work even to introduce its fundamental notions like continuity or derivatives (after all, it took 2 centuries justto define these notions properly). To get a feeling for the power of its methods, say bydescribing one of its important applications in detail, takes years of study. If you want to become a mathematician, computer scientist, or engineer, this investment is necessary. But if your goal is to develop a feeling for what mathematics is all about,where is it that mathematical methods can be helpful, and what kind of questions domathematicians work on, you may want to look for the answer in some other fields ofmathematics. There are many success stories of applied mathematics outside calculus. A recent hot topic is mathematical cryptography, which is based on number theory (the study of positiveintegers 1,2,3,. . .), and is widely applied, among others, in computer security and electronicbanking. Other important areas in applied mathematics include linear programming, codingtheory, theory of computing. The mathematics in these applications is collectively calleddiscrete mathematics. (“Discrete” here is used as the opposite of “continuous”; it is alsooften used in the more restrictive sense of “finite”.)