"if 50% to 75% of cases are asymptomatic that means 25% to 50% are symptomatic."
then I go ahead and choose a number (400000) which is on the optimistic end of this range - 80894 is 20.2% of 400000 - I believe that is quite clear, if 80894 is 20.2% of 400000 and 80894 is the amount of total cases counted in China (no longer the case) then I am assuming 79.8% people asymptomatic that have not been counted! (although of course I did some simplifying of things around so my percentages and numbers are not exact, but I think given the linked article slightly under 320000 people being asymptomatic and 80894 being symptomatic is a very optimistic take)
what number do you want to assume is not counted? millions? I assume that from your earlier post but that does not follow from the 50% to 75% cases are asymptomatic.
Obviously if 50% to 75% are asymptomatic and you had 1 million people infected all together (symptomatic and asymptomatic) that would mean you needed to have at least 250000 (25% of a million) to 500000 (50% of a million) people symptomatic. But we don't have those numbers symptomatic, we have slightly under 81000.
I'm not taking the exact 75% number here in the following - but close, and I will do some hasty approximations.
Current total cases (maybe off by some hours) is 80,894.
80894 is 20.2% of 400000.
400000 - 80000 = 320000.
So yes, given the article's premises 320000 is pretty much on the optimistic side for humanity.
on edit: but once again my math is probably off somewhere so correct it if you see some glaring error in my reasoning. Also note these numbers are for China, of course.