Select an empty cell somewhere and put a 1 in it.
Copy that cell into the clipboard (Crtl+C).
Select the cells that you want to multily by 1, right click one of them and choose Paste Special…, in the resultant dialogue box, choose options Values and Multiply, click OK.
In code you might use (after selecting the range):
Code:
Sub blah()
With Range("A1000000")
.Value = 1
.Copy
Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlMultiply, SkipBlanks:=False, Transpose:=False
.ClearContents
End With
End Sub
where I've used cell A1000000 as an out-of-the-way cell.