Open A New Window
Sometimes
it is very useful to have another copy of the same spreadsheet open.
For instance, the first Window could display the monthly sales while
the second Window could show the sales totals. Seeing both
spreadsheets saves time. It is easier than switching between
screens.
Try
This: View and Arrange Windows
Go to View-> New Window.

The new Window will be added to the stack of
spreadsheets you have open.
Now, go to View-> Arrange.
You will be prompted to choose how you would like to
arrange the Windows.