system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5: why is 0 next to 9 on keyboards, rather than 1?
gpt
Older typewriter layouts tried to do everything they could to have less keys.

Some didn't even have a '1' - you were supposed to type a lowercase "L" instead of a digit 1.

And they didn't even have a '0' either.  You were supposed to type a letter 'O' instead.

The '1' key got added first, and then later the '0' key got added.

By the time the '0' key got added, the easiest place to find the room for it was to the right, not, the left, of the numbers that were already there.  Also, that made it adjacent to the letter 'O' that was already there so it was conveniently similar to what people were already doing to reach your finger up there to hit it.