Determine If Cell Is Number & Round

It's been awhile since I've done this...and I tried searching for the solution but to no avail.

I'm trying to edit the contents of a series of numbers by using the Rounding function. When I execute my macro on the next cell, it uses the value of the original cell when the macro was created. Here's a copy of my macro:

Sub RoundTest()
'
' RoundTest Macro
' Macro recorded 7/26/2007 by Aramark Uniform Services
'
' Keyboard Shortcut: Ctrl+l
'
ActiveCell.FormulaR1C1 = "=ROUND(2103.86,0)"
ActiveCell.Offset(1, 0).Range("A1").Select
End Sub