Remove Tasks in Calendar
Check off tasks with the checkbox when you're done.
Hide completed tasks
- Open Google Calendar.
- On the left side under "My calendars," click Tasks. If you don't see Tasks, next to Reminders click the Down arrow
Switch to Tasks. Your tasks will open on the right.
- Click Actions
Clear completed tasks.
You can review your completed tasks later with Actions
View completed tasks.
Delete tasks
- Open Google Calendar.
- On the left side under "My calendars," click Tasks. If you don't see Tasks, next to Reminders click the Down arrow
Switch to Tasks. Your tasks will open on the right.
- Select a task, then click Delete
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You can bring back a deleted item by clicking View recently deleted items from the confirmation message that appears.
Return the item to your list by selecting "Undelete task" 
Turn tasks off
- Open Google Calendar.
- On the left side under "My calendars," find Tasks.
- Click Tasks to hide your list.
You can tell if Google Tasks is hidden if the square next to it is an outline.