An apparatus and method for a solution that permits a carpenter to make exact, on-the-spot time-efficient cross-cuts of their boards while holding the board in one-hand and the circular saw in the other hand. A cross-out apparatus includes a guide system including a housing and a range of motion control for defining a processing path for a guide element as it moves from a first position to a second position relative to the housing; a workpiece coupler, coupled to the guide element, for defining a desired processing orientation with respect to a workpiece for maintaining the desired processing orientation as the guide element moves from the first position to the second position; and an attachment system, coupled to the housing, for cooperating with a hand-held power processing tool to position a processing implement at a reference location relative to the workpiece and at the desired processing orientation, the attachment system coupled to the housing so the guide element maintains the desired processing orientation along the processing path from the reference location during use of the hand-held power processing tool to process the workpiece.