Their math was flawed, but I’m not really sure how to explain the math part better. I get what they were going for, though.

It’s closer to decimal divisions of an inch, so a .223 caliber bullet would be a hair shy of a quarter of an inch (.25) wide.

Edit: just realized you had the second part of that already

maybe a little less sweet

I see what you did there

You’re fine - I grew up in a rural state, and I thought they were super rare until I lived in a city where the public transit system gave them as change.