With Excel's PRODUCT function, you supply a range of numerical values, and it returns the product of those values. When working with financial data, especially percentages, and you want to get a return for that date range, you have to add one to each cell in the range first before you take the product. So you have to create a completely separate column that is just the previous column's values plus one. This is very time-consuming when you have a lot of data, and quite a waste. Is there a way to add one to each cell in the range before applying it to the PRODUCT function, or is there a way to write a new function that adds one to each value and then returns the product?