"I have six classes in the university."
Translation:Yo tengo seis clases en la universidad.
As a credentialed teacher, it's best practice to have students reïnforce learning by having students spell out the words for numbers instead of using a numeral... using a numeral activates a different part of the brain. Make peace with that and you'll be fine... there is method to the 'madness'
Duolingo does not read every single comment, only some. However, the creators will read any reported problems. To report, just click the "Report" button next to the "Discuss" button. Both are under the "Correct/Incorrect" sign after it is corrected. (At least, on a computer.)
Hope this helps!