Armhole problem

I am working on the armhole of my sweater. I am to bind off 5 sts on each side. How can i continue my armhole if the last 5 sts are bindoff?

K you would bind off the stitches in a two row operation. Bind off the first five stitches on the row, then work to the end, turn, bind of 5 stitches and work to the end of the row, Now you would do your shaping as called for int he pattern (if there is any).
Hope that helps. Sometimes designers forget that not everyone is at the same place in experience as they are and sometimes assume that you know what they mean. Or maybe this is their first go at writing patterns and don’t quite have it down yet.