You would need macro for that


Private Sub Worksheet_Change(ByVal Target As Excel.Range)
If Intersect(Range("A2"), Target) Is Nothing Then Exit Sub
Application.EnableEvents = False
Target.Value = Target.Value * 0.3
Application.EnableEvents = True
End Sub

will change whatever number is entered in A1

for information see

http://www.mvps.org/dmcritchie/excel/event.htm

--
Regards,

Peo Sjoblom


"Eric Whittaker" wrote in message
...
I am trying to create cells that will make calculations for me. For
example, I want to enter the number 140, and have the cell automatically
make the calculation to 30 percent of that number. Any suggestions? Thanks.