Pattern Help - Knit 5, Cast off 6. How is that possible?

Hello all,
I’m doing thispattern. I’m on the “Leg Openings” section and it states:
[B]Leg Openings: Next row[/B]: (RS). K5 ([B]5[/B]-7-[B]11[/B]). Cast off 4 ([B]6[/B]- 6-[B]10[/B]) sts. K36 ([B]46[/B]-56-[B]80[/B]) (including st on needle after cast off). Cast off 4 ([B]6[/B]-6-[B]10[/B]) sts. Knit to end of row.

I’m doing the second size. How is it possible to knit 5 and cast off 6??

Knit 5 sts, then knit 2 more and pass one st over the other, k1, pass a stitch over, etc until you’ve cast off 6 sts, then knit the rest of the sts.

Thanks. So I need to add 2 more stitches each time it calls for casting off?
I haven’t knit in a few years so my brain is foggy.

You don’t ‘add’ sts, just knit 2 more. You always have to knit 2 in order to cast off 1, even on the last row. And you only count the sts you pass over, not the ones you knit.

Thanks!