You will need to create a new account using Scholastic Achievement Manager. The program comes packaged with FASTT Math and it is developed for teachers and administrators. Launch the program, sign in using your manager account, open the yellow Roster tab and click Add a Student:
After that, fill up the provided fields and configure a username and password for your student. After you finish, click Save.
For further information, I suggest you access the first link from Google search engine.