The Marco below, written by Barrie Davidson, will do what you want.
Sub Insert_rows()
' Written by Barrie Davidson
Dim insertNumber As Integer
On Error Resume Next
Range("A1").Select
insertNumber = CInt(InputBox("Enter number of rows to insert"))
If insertNumber <= 0 Then
MsgBox ("Invalid Number Entered")
Exit Sub
End If
Do Until Selection.Value = ""
ActiveCell.Offset(1, 0).Range("A1:A" & insertNumber).Select
Selection.Insert Shift:=xlDown
ActiveCell.Offset(insertNumber, 0).Select
Loop
Range("A1").Select
End Sub