system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do large numbers before the decimal point get separated by commas in groups of 3, but numbers after the decimal do not?
gpt
Most of our numerical punctuation rules as used by the general public come from accounting, and in accounting there is no reason to use decimal points farther out than the 1/100th place but there is reason to use thousands and millions indicators.