Is the 5" the wrist part? It sounds like you're binding off for the thumb or thumb hole. K2p2 then bind off 4 stitches and contine from there in the ribbing pattern to the end of round.
To bind off in ribbing you bind off with the yarn just like you do for ribbing. Here's a video. Ignore the first slipped stitch though, just knit it like you always do.
http://youtube.com/#/watch?v=1DGXMee...%3D1DGXMeeXaAE
I'm hoping the link works since I'm on my iPad. If not look up "bind off ribbing" on you tube.