No, seriously, how did they even do anything?

Spreadsheet software existed before Microsoft Excel, starting with VisiCalc, written for the Apple II computer in 1979. Also, back in the day you didn't just load software to do something but actually wrote a lot of little snippets in basic as a way to repetitive math. One of the first things I learned was a little universal basic program of less than 10 lines for figuring out your employees salary.