How come "mam 8 dolarow" is not ok?
Well it might be "o" instead of "ó" ;)
No, from what I noticed, for missing diacritics you get a "warning". It was probably the digit "8" instead of the word "osiem".
Yes, we want to teach you how to spell the numbers, so we don't accept digits.
that works when you're spelling the digits in Polish but when you are spelling the digits in English it shouldn't make a difference
When answering in English, digits should work automatically. At least for small numbers (1-100?).
why isn't it mam osiem dolary
Most numerals actually take the Genitive case, so it's "osiem dolarów".
The ones that DO NOT take Genitive are 1, 2, 3, 4 and those that end with "dwa", "trzy", "cztery" (so 22 takes Nominative but 12 takes Genitive as it doesn't end with the actual word "dwa").