Install the first row of hardwood planks, starting in the corner of the room and attaching the planks together one by one in a single row until you reach the far end of the room.
Measure from the top edge of the last full plank, not from the edge of the “tongue.” The tongue will be covered by the groove of the next plank.
Cut the final board in the row 3/4 inch shorter than the measurement with a chop saw. The cut end of the board will be closest to the wall.
Carry the cut-off section and use it to start the next row of boards. There is no need to cut another board or to use a new board to start the next row.