I might be late to the show but the latest version of Excel offers multiple windows open in the same workbook. For example, say you want to enter results from one worksheet into another. Or you’re looking at a large worksheet and want to see results in the lower corner and upper corner at the same time.
Select View, New Window. You can repeat as needed from the original window.
Here’s a screenshot:
Here’s the result spread over two monitors:
And why this is so useful:
Wish I’d known this 10 years ago. Maybe I will buy that 4th monitor after all.