Once a student has been dropped from a classroom, at any point they can be recovered thereafter. Here is how to recover a dropped student.
1) Click on the "Classes" tab after logging into your account.
2) Select the classroom that the student was dropped from, located on the left-hand side.
3) Once the classroom is selected, you will want to click on the "Dropped Students" tab above the green bar.
4) Once you are on the "Dropped Students" tab, you will want to click on the green "Recover" button to the far right of the student's name, who you want to recover (under the "Manage" column).
5) Once you recover the student they will appear in your classroom when you click on the "Manage Students" tab.
Please note that if you need to transfer a recovered student from one class to another, then you can follow the steps on this page: How To Transfer or Share Students