On the start date of the Challenge by default the Challenge will appear in the Activity panel in the student's City page. If you want to only have your students would on the Challenge you can restrict them for an hour, here is how.
If your students do not see the Challenge it might selected another Activity by accident, to go to the Challenge click on the green Activity panel and select the Challenge from the available activities.
If the Challenge is not appear on the list, it could be that it has not yet started or that the student was not included in the Challenge. Do check the Challenge settings from your teacher account.
To start playing in the Challenge the student will just need to play any game as normal their answers will count towards the Challenge as long as they are in Challenge mode.
In the blue panel below the Challenge, the student will see a Progress bar, this will show them how many correct question they have gotten correct and how many more they have to go before reaching the target.
If they click on the Progress panel they will be able to see:
- Number of correct answers they have so far
- How many days are left in the Challenge
Once the student reaches the target they will be rewarded with bonus coins.