I am reading a stitch pattern book, and in the lace section all the patterns say something like "8 +3" Now, I know that the 8 is the number of stitches in the pattern and then you repeat it across the row. However what does the "+3" mean? At first I thought it meant making some kind of border at the edge, but if so, why would it be in a stitch pattern book where it is simply describing the pattern and has no idea what you are making? If I decide to do the pattern 3 times across a row, I would cast on, I assume, 8+8+8+3=27 stitches. But what do I do with the extra 3 when it comes time to knit?