In this latest version of Excel 2013, Microsoft has modified the default mode that allows users to manipulate many different Excel windows at the same time. You have to go to the settings inside to do this with previous versions of Excel, but with this version you just need to use the mouse cursor to adjust.
Tutorial on how to open multiple different worksheets in EXCEL 2013
Supposing you have 3 worksheets you want to work at the same time. You open all 3 of these spreadsheets.
In spreadsheet 1, when opening the window in full screen mode as follows:
You press the Windows key + Left arrow on the keyboard. At this point, the window of spreadsheet 1 will immediately be collapsed to exactly half of the screen on the left:
Similar to the 2nd spreadsheet:
You press Windows Key + Right Arrow on the keyboard. At this point, the window of spreadsheet 2 will also be immediately collapsed to exactly 1 half of the screen on the right:
You can use your mouse to point to the edge of this spreadsheet 2 window, hold down the mouse to scale the workbook down to the position and size you want as shown below:
Similar to what you do with workbook window 2, in workbook window 3 you can also scale down to the position and size you want to be able to manipulate all 3 worksheets at the same time as follows:
So you already know how to open different spreadsheets in Office