I often cut larger strips of fabric using my 12.5" square ruler. I would cut the 9.5" strips, then subcut into 9.5" squares. I also use my 12.5" square when cutting multiple strips, like 3.5", I would cut at 10.5", 7" and 3.5". I had seen a quilt teacher on TV cut this way - after straightening the end, I would subcut the strips and never move the ruler, makes for more accurate cuts this way. I know this may be confusing, but use the method that works best for you. I will say that I seldom use the cutting mat to cut squares or strips, but that's just me.