Shoulder shaping


I am making my first sweater and so far its been simple. But i am confused at the back shoulder shaping.

When i cast on i cast 70 stitches. So what do i do with the stitches left after i cast off 7 and knit 42?

Help with neck/shoulder shaping instructions

Welcome and congratulations on making your first sweater!
Bind off 7 and knit across the remaining sts, turn at the end of the row and bind off 7sts then knit across the rest of the sts. That’s rows 1 and 2. Repeat these directions for rows 3 and 4. For rows 5 and 6, bind off 6sts at the beginning of both rows. You’ll have about 30sts remaining. Place those sts on a holder for later.
What is the name of your pattern?