This manual is meant to explain usage of functions that are available in Excel. Examples are provided as I have worked through the functions with multiple efforts to understand the operation of the function. A function that sums values is easily understood, if explained adequately with examples of how to do correctly. A function that predicts the present value of a Bond or the balance on a loan is not so easily understood. Examining the HELP provided in Excel often did not provide the insight needed to understand the Function. Searching on the Internet often only provided the same text with the same examples. Many of the functions I have provided multiple instances using different values for the variables included in the function. The key to understanding the operation of a function is to understand the variables associated with the function.