Yesterday I introduced you to the idea of words as numbers. There are many ways to create a map between words and numbers. For example, we could assign them the number that represents their position in the dictionary. That would make words that start with “A” have smaller numbers while words that start with “Z” would have the largest numbers.

There are also ways to treat the words *themselves* as numbers. We can interpret the letters the same way we do digits. Each letter has an assigned numeric value, and then a string of letters—just like string of digits—forms a number. The scheme I showed you yesterday allows us to treat (only!) single words as numbers.

Now let’s extend this so that entire sentences—or even entire *books*—become numbers!