Spreadsheet programs (like Microsoft Excel) are built and optimized for solving complex math problems. But I would guess that the percentage of people that use them for that are less than 0.1 %. Instead, spreadsheets are widely used for organizing data; which is logical since data is usually organized into tables - which is essentially what a spreadsheet is - a big table (or grid). Plus, spreadsheet programs a lot easier to work with than database programs, which makes programs them the popular choice for presenting data.
The nice thing about Microsoft Excel nowadays is that you can organize your data and use it to produce a useful document. Below is an example of a spreadsheet I used to create a basketball league for a youth church league that I ran. I used the same spreadsheet document to list out the teams & dates and to figure out the game schedule by moving teams around. Then applied a small amount of formating it and used it to generate a PDF document of the schedule that I distributed to the coaches.
Basketball Schedule
Obviously, the possibilities are endless. There are many more examples of how you can use Microsoft Excel to produce documents that are quite useful. I will continue to share them as fast as I can. Of course, if there are other documents that you would like to see, be sure to request them here.