Q: but if there isn't, the 4s remain and it rounds to a 0. you don't have infinite time to check for the 5. what do you round it to, 0 or 1?
A: clearly 0. there's no reason to round it to 1 unless you are following some bizzaro rounding rules. the number is significantly closer to 1, no matter what. .44445, .445, .45, heck even .4999999 are unambiguously closer to 1. the only way that .4444444444445 could possibly end up as 1 is if the number is being rounded 1 digit at a time, over and over again, destructively. and if that happens then the process needs to be fixed because that's a serious corruption. rounding the entire number at once, it unquestionably goes down. there's no rule in the world that says even .45 should go to one, any more than 45 should go to 100. again, the only way 45 goes to 100 is if one person rounded 45 to 50 and then handed it off to someone else without telling them that it came from 45 and then that second person took the new 50 and rounded it to 100. in which case, again, there is a serious communication breakdown here which is corrupting the results and should be investigated