Open the first page of a book about learning Python, and the chances are that the first examples of code you’ll see will involve numbers. There’s a good reason for that: numbers are generally simpler to work with than text – there are not too many things you can do with them (once you’ve got basic arithmetic out of the way) and so they lend themselves well to examples that are easy to understand. It’s also a pretty safe bet that the average person reading a programming book is doing so because they need to do some number-crunching.