The book reviews matheamtical concepts and techniques that are prerequisites for calculus. It is intended to be used along with a calculus text in a first course in calculus. It sets the stage for calculus topics and uses calculus terminology and notation. The four distinct modes description, algebraic forms, graphs and data are used in each topic. Informations are translated from one mode to another. Exercises and solutions are given. The single chapters are companions to the topics: Cartesian coordinates; functions; limits; continuous functions; infinity; change rates; differentiation rules; trigonometric functions; implicit and repeated differentiation; related rates; linear approximations and differentials; exponential, inverse, and logarithmic functions; extreme values; curve sketching; antidifferentiation; area and Riemann sums; definite integral.