In the 3rd grade mission, getting your first question right will result in seeing the rather misleading message "See if you can get the next 0 questions":
Of course, skipping them or not getting them right won't lead to progress. There is no workaround but to get the questions right...
We apologize for the issue, which has been reported to the troubleshooters.
Internal ticket: 225304755916208
Jan. 4th 2017