When looking at old typewriters, you’ll notice the key for number one is missing.

It’s not because someone took it out or because it broke. Here is another one:

So did you find out why the one key is missing?

Here is the answer: the number one key was not implemented by design. Instead, the L key – l – in lowercase, was used in its lowercase form as a letter or a number, because a  lowercase l looks like a one. That allowed manufacturers to save some space in the overcrowded area where hammers were located.