Numbers
Delete a spreadsheet in Numbers on Mac
Important: When iCloud Drive for Numbers is on, deleting a spreadsheet from iCloud Drive removes it from iCloud and from all other devices and Mac computers where you’re signed in to the same Apple Account. Turn on iCloud in System Settings in the Apple menu 
Delete a spreadsheet
If you don’t know where the spreadsheet is, locate it first.
Select the spreadsheet, then do one of the following:
Drag the spreadsheet to the Trash icon in the Dock.
Press Command-Delete on the keyboard.
To empty the Trash (and permanently remove the spreadsheet from your computer), click and hold the Trash icon in the Dock, then choose Empty Trash.