Spreadsheets often utilize arithmetic functions, such as automatically adding up all the values of one particular column. These functions are necessary for budget and invoice spreadsheets.
While it may be true that some of the things mentioned above could be done in a word processor, spreadsheets have a huge advantage over word processors when it comes to numbers. It would be impossible to calculate multiple numbers in a word processor and have the value of the calculation immediately appear. Spreadsheets are also much more dynamic with the data and can hide, show, and sort information to make processing lots of information easier.