Deleting Data
Deleting data may seem simple enough, but doing it incorrectly
can really mess up your spreadsheet. Follow these rules and you will be fine.
As a general rule, select the cells that contain the data you
want to delete, and then select Edit | Clear | All to delete data.
This is the same as hitting the Delete key on your keyboard.
Make sure to delete entire rows or columns as described on the
'Rows & Columns' page.
Do not delete individual cells unless you have a specific
reason for doing so.
Do not "blank-out" (i.e. use the spacebar) cells to delete data.