Sub unmatched()

spr3RowCount = 1
spr2RowCount = 1
With Sheets("spr2")
  Do While .Range("A" & spr2RowCount) <> ""
     FindNum = .Range("A" & spr2RowCount)
     With Sheets("spr1")
        Set c = .Columns("A:A").Find(what:=FindNum, _
           LookIn:=xlValues, lookat:=xlWhole)
        If c Is Nothing Then
           Sheets("spr3").Range("A" & spr3RowCount) = FindNum
           spr3RowCount = spr3RowCount + 1
        End If
     
     End With
     spr2RowCount = spr2RowCount + 1
  Loop
End With

End Sub

There is not a single function that does this, but Chip Pearson illustrates
how to do this with a combination of 3 functions assembled into a formula.
Look at the 3rd example on this page for Extracting Elements From One List
Not On Another List.

http://www.cpearson.com/excel/ListFunctions.aspx

Once you have the list on spr3, select that list and Copy/PasteSpecial
Values to remove the formulas and keep the results. Now sort the results to
remove blank rows.

Mike F