Confused about this pattern

[Jan in CA]

I'm confused about the instruction in this pattern. I've never seen it written this way before.
http://starry.neo-ilove.com/?page_id=227

- After the 9 rows it says:

Beg RS row K15 ssk 5, k1, k2tog 5, K2end

I don't understand what the number means in this case. Do I ssk 5 times..as in over the next 10 stitches or do I ssk 5 stitches all at once? Same with the k2tog.