You can always customize the curriculum for each student individually after the students took the Placement test.
Teaching a multi grade classroom? Check out this article to know how to tune Happy Numbers for multiple grade classrooms!
In your teacher’s account go to “Reports” menu to view the list of your students. Click on a certain student to see his/her current progress.
If you switch to "Assignments"/"All topics" you will be able to customize the number of lessons assigned to this particular student by selecting necessary modules or topics from Happy Numbers curriculum.