This book comprises three major parts, each containing some solved examples related to real life situations. The first part is the Calculus, it includes theories and formulas accompanied by solved examples. Readers will be able to think critically and manage to solve business problems using Calculus tools. The second part of the book is the Numerical Analysis, where MATLAB software is used to solve Calculus problems numerically. In the same part, algorithms are provided to be used while solving problems analytically. The comparison is made between analytical and numerical solutions. The last part is really the application of Ordinary Differential equations known as mathematical modeling of nonlinear problems. Some applications such as, population dynamics, chemical reactions, Lorenz equations and epidemic models were analyzed. During the analysis different figures were drawn showing the model numerical solution. Exercises at each Chapter in the book are provided.