Adding value of two cells to get result in 3rd cell

[DocAElstein]

this is your worksheet

_____ Workbook: Book1.xlsm ( Using Excel 2007 32 bit )

Row\Col	A	B	C	D	E	F
1
2
3		5			2
4

Worksheet: Sheet1

This is your macro, as given by you in your uploaded file. It is incorrect. It will not work.

Sub add()
Range("C8").Value = Range("B3").Value + Range("E2").Value
End Sub

This next macro below works fine for me. This is the correct macro for your worksheet

Sub add()
Range("C8").Value = Range("B3").Value + Range("E3").Value
End Sub

[Anshu]

Well, then there may be some fault by my side which I'm unable to find out.
I'm using latest build of MS Office Pro Plus 2019. I should check the code with older version. It may help.
Thank you!!