I added students to a class roster where texts had already been assigned. How can I assign those assignments to the new students?

If class assignments are less than 30 days old, we will automatically assign them to new students who join that class.

If the assignments are more than 30 days old, we do not automatically assign them, but rather mark the students as exempt. Teachers can assign these assignments to students from the Assignment Report. 

You can get to the Assignment Report from the Assignment Dashboard, or by clicking the graph icon on the assignment page's assignment progress bar.

Scroll to the bottom of the Assignment Report where there is an Exempt from Assignment list and use the checkboxes to assign the assignment to your new students.