When you hover the to-do, you can mark the to-do as completed by clicking on the tick. The to-do will then be moved to the bottom of the list.
Follow the steps below to mark a to-do as Complete:
Expand the stage that contains your to-do
Click on the list icon to the right of a task to open the to-do menu
Hover over the to-do you wish to mark as Complete
Select the tick to delete your to-do
The numbers next to the list icon will update to reflect the number of to-dos remaining.