"How many girls do you teach?"
Translation:Quot puellas docetis?
What is the difference between “quot” and “quanti”? This sentence wants quot, but it seems to me there were other sentences a few skills back that wanted quanti. I think those were often about “quanti nummis panis constat.” (Not sure I have that sentence remembered right.)
Quot and quantus.
Quot is used, as a question word, to ask for a number, how many.
Quantus is used to ask a quantity, how much, how big, how large. Or a price (="quanti")
In think the latin typo detector is by far too lenient. Now that I'm almost through all exercises up to level 5 I'm still unsure if or when it is urbe, urbs urbem or in this case puellas or puellae because everything goes, they are just marked as typos, so I don't bother, However adding or missing an -s when writing verbs in English are always a big Red No-No. Please fix this before leaving the beta stage.
Yes, it's a known bug. But, please don't ask them to fix it here, as it's not the place for the reports: they won't read it here, we are on the help-between-users forum, only.
And, anyway, as it's a known bug, they can't even work on it, as it's at the programming level, and they are not those who write the software. They are only here to add content, not to repare things under the hood.
Your problem is the same than mine. It's impossible to learn with such a typo system. (They should allow zero typo by the way, it would be better than too many).