Assign lessons to units

To add a lesson to a Unit, open the lesson plan and click the Unit + button. Then select the Unit you want to assign the lesson to.

Anywhere the Unit + button is displayed on a lesson means you can assign the lesson to a unit. 

If you see this button displayed with a number in place of the plus sign, it means that the lesson has been assigned to a unit. You can still click the button, to change the unit assigned to the lesson.