Add Rounding off Formula to selected columns

Hi
Please help me to create VBA code. If selected columns cells contain number then rounding off formula to be added ( Round,0) if any cells does not have numbers, to be ignored round formua.( In my range of columns I have text and blank cell also)

Hi Maras_mak. Thank you so much. The below codes i expected.

Sub Round_2()
Dim rng As Range, e As Range

Set rng = Selection.SpecialCells(xlCellTypeConstants, 1)
For Each e In rng
e = WorksheetFunction.Round(e, 0)
Next
End Sub