In this course, we will learn how to structure, analyze, and solve business decision problems using Excel spreadsheets. We will focus on problems involving decision-making and risk analysis. The emphasis of the course will be on systematic, critical and logical thinking, and problem solving using spreadsheets as our primary tool. We will start with the basic techniques of good spreadsheet modeling and organization, and proceed to introduce a variety of modelling techniques and approaches. All along, we will critically think on how to interpret the results of our analysis process in the context of decision-making. These will be illustrated by building and analyzing problems in finance, marketing, and operations. While the underlying concepts, models, and methods of this course are mathematical in nature, we will develop them on the more intuitive and user-friendly platform of spreadsheets, always focusing on the ideas and insights, rather than the underlying mathematical details. The spreadsheet approach to problem solving is more accessible to managers, as they often find spreadsheets a natural medium for organizing information and performing "what if" analyses. We will study how to use Excel and various add-ins to perform such analyses and interpret them. We will study three specific techniques: optimization, decision trees, and simulation. The usage of these techniques in practice can improve the decision making process in many situations.