If your school is rostered, your district takes care of your teacher accounts for you. You will not be able to add teachers to your class manually. See How can I tell if my school is rostered and what does that mean? for more information.
If your school is not rostered, then ST Math administrators can now add multiple ST Math teachers or co-teachers to a class. Once teachers have been added they will be able to view reports and manage the class.
1. Click the class you want to add the teacher to
2. Click on Settings
3. Scroll down to Add Teacher
4. Type in additional ST Math teachers names, and select their names from the dropdown menu