I have another dumb question.
How can I enable a macro/subroutine to use the undo
command?

The sub is simple:
Private Sub CommandButton3_Click()
Range("H16").Value = (Range("I16").Value + Range
("J16").Value) * Range("F16").Value
End Sub

Take a look at John Walkenbach's explanation:

Undoing a VBA Subroutine
http://j-walk.com/ss/excel/tips/tip23.htm

In article ,
"Jerett" wrote:

I have another dumb question.
How can I enable a macro/subroutine to use the undo
command?

The sub is simple:
Private Sub CommandButton3_Click()
Range("H16").Value = (Range("I16").Value + Range
("J16").Value) * Range("F16").Value
End Sub

Application.Undo
Apparently it must be the first command in your macro

"Jerett" wrote in message
...

I have another dumb question.
How can I enable a macro/subroutine to use the undo
command?

The sub is simple:
Private Sub CommandButton3_Click()
Range("H16").Value = (Range("I16").Value + Range
("J16").Value) * Range("F16").Value
End Sub