system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does a million/billion/trillion start at 1000^2 instead of 1000^1?

Million is for 1, billion is for 2, trillion is for 3, quadrillion is for 4 and so on, they're off by factors of 1000, but they start at 1000^2 instead of 1000^1 . How come it's like that? I feel like million (being one) would be 1000^1 since it seems like it'd make sense.
gpt
They made more sense before we changed their meanings. Originally, a billion was 1,000,000^(2) and a trillion was 1,000,000^(3). Then 1,000,000,000 was just a thousand million, or sometimes a milliard. Then we changed from that "long scale" to the "short scale" meanings that are now more common (at least in English-speaking countries).