Using New Window and Arrange

If you have more than one document open, you can view them simultaneously in a number of ways. One way is to re-size and move the documents so that the desired part of each can be seen at the same time. Another way is to use 

With three open documents, the Tiled option arranges the documents with the active sheet occupying the left half of the screen the other two sheets each occupy one-quarter of the screen, one above the other. With four documents Tiled, each occupies one-quarter of the screen. Click on any document to make it the active sheet. Double-click anywhere on the solid border between the windows to undo the arrangement. 

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