This slide is pretty self-explanatory: Take (2) sheets of 4x8 plywood and make (6) 16 inch wide planks out of them.

Note: Don't worry about the kerf (the bit the saw blade turns into sawdust.) Mark the lines as shown and cut the line. I use a plain old jigsaw for the long, straight cuts. I concentrate on cutting the line, and even if I waver a bit, I try to never leave the line. I end up with pretty straight cuts.