patern question

my pattern says:

with RS facing, slip centre 31 sts onto a holder,
rejoin yarn and K to end.

I got a bit confused at this part and was wondering if you could put it into simpler terms?

Thanks
Pat

That sounds like shaping for a neck, yes? Assume you have 51 stitches on your needle. Starting on a RS row, you will knit the first 10 stitches. Then slip the next 31 stitches onto a holder (a piece of yarn or a cable, whatever. These will be worked later. ). Then attach another ball of yarn and knit the remaining 10 stitches. This will allow you to work both the left and right sides.

In other words, X = total # of stitches on your needle. Subtract 31 from X and then divide by 2. That gives you the number of stitches to knit before slipping the 31 middle stitches onto a stitch holder. Make sense?