How To Reference Microsoft Excel Cells into Other Worksheets

Here is the formula on how to reference cell in other worksheets:

Name of Sheet exclamation point Name of Cell. How can we use it?

Its like for example you have three sheets in your excel file called Sheet1,Sheet2,Sheet3 and we need to sum-up the figure from Sheet2 cell named A1 and Sheet3 cell named A1 from Sheet1 cell named A1. the actual formula would be like this =Sum(Sheet2!A1+Sheet3!A1)

 this is the result