How can I make round neck

[Nargess]

Hi,

I am quit new to knitting but I decided to make a short vest, but I couldn't make the neck.
So here is the link to this pattern:
(sorry I wasn't able to post it because it's my first post!)
And the part that I have problem with is "When piece measures 29-31-33-35-37 cm cast off the middle 14-14-14-18-18 sts for neck and dec to shape the neckline on every other row: 1 st 5 times = 22-24-24-24-26 sts left on each shoulder." from the back piece!
I don't know how to cast off the middle of the work?
I appreciate if somebody could help me with this.

Thanks,
Nargess

[salmonmac]

Find out where the middle 14 or 18 sts are in your example. Mark them and when you work over to the first of the 14 (or 18), knit it onto the right hand needle, knit the second st onto the right hand needle and then pass the first st over the second. That's one st cast off. Continue