Hello, and welcome to an introduction to spreadsheets and models. My name is Don Huesman and I'm the managing director of Wharton online and I'll be your guide in this course on spreadsheets and models. The course will cover four topics. First, we'll look at the electronic spreadsheet, as a tool for thinking with numbers, for examining more closely, opportunities that come our way, by sketching out their financial dimensions. In the process, I'll review with you basic spreadsheet navigation and spreadsheet operations. Next, we'll move from using spreadsheets for calculations to building models out of real world business activity. We'll look at how to pull apart the different elements of a business scenario. What do we know? What do we assume about the environment? What decisions do we face? What outcomes or metrics do we care the most about? What insights can we draw? Then we'll turn to implementing some basic mathematical functions in spreadsheets, to help with making predictions, forecasts and determining optimal choices. We'll experiment with some of Excel's statistical tools to see how elements of our model business scenario are related to each other. Finally, I will demonstrate for you the use of a spreadsheet to guide decisions through a technique called linear programming. Many of these skills will also be helpful to you as you work through the other courses in the business and financial modeling specialization. In this lecture, I want to share with you a little of the context in which spreadsheets emerged, walk through the differences between using a spreadsheet for simple calculations and using a spreadsheet to think through and evaluate opportunities. Also, I want to make sure you have the tools you need to get the most out of this course. But first a little history. Computers have been used to support business decisions since their beginnings in the 1940s. However, something special happened in the 1970s, the invention of the personal computer. For the first time, individuals had access to affordable computing power. The name tells some of the story. It's not a microcomputer, which is what the engineers first called it, it's a personal computer. It's for me, not just for my company. It's a device for ordinary consumers. Now many people attribute that change to the brilliance of Steve Jobs and Steve Wozniak, and they certainly deserve a lot of that credit but I give these two fellows much of the credit, as well. Dan Bricklin and Bob Frankston were students in the late 1970s in Boston. As I heard the story, in some of their accounting classes at that time, students were asked each week to review financial ledgers and then recalculate all the numbers on them based on changes requested by the professor. Now that meant some very long hours of work with a handheld calculator. Dan and Bob thought maybe there could be a better way. They purchased one of the new microcomputers that were coming available at that same time, and they wrote a program for one of them that put the financial ledgers on a computer screen. The result was the electronic spreadsheet, VisiCalc, the original killer application. I was an entrepreneur in the PC industry at that time and for my money, it was the spreadsheet that drove the huge sales of Apple computers and launched the personal computer revolution. I mention this because I wanted to share with you some of the excitement that was generated by the emergence of the spreadsheet. Before the electronic spreadsheet, accountants and financial analysts use ledgers like those pictured. The spreadsheets certainly made those types of accounting processes more efficient but the spreadsheet is more than that. After the release of VisiCalc, it quickly became apparent that spreadsheets are not just machines for running calculations. A spreadsheet can help you play with ideas, examine opportunities from a quantitative perspective. Using a spreadsheet, you can model the future, play around with different decisions, different assumptions about how a business scenario might unfold, think with numbers.