HELP! Peter Pan Marino baby P1187

I am knitting the back and at the shaping armhole stage while casting off. The instructions are:

Cast off 4 stitches, patt until there are 4 stitches on the right needle, (p2tog) 3 times, patt 9 sts, (p2tog) 3 times, patt 4 sts.

How can I do all that with only 4 sts on my needle? Do I leave the 4 sts on the right needl then start working again on the left needle?

Any help would be appreciated I’m quite a novice but thought I was doing ok!

Is this it? http://www.deramores.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/p/1/p1187.jpg
What was the pattern for those 4 stitches on the rows before?

Yes that’s the pattern.

I’ve took a wee photo of the instructions:

Sounds like you’re still doing fine. There are enough sts to complete the pattern depending on the size you’re making. Remember you’re casting off 4 sts on this WS row and then working only the next pattern sts (probably 3sts?) so that you have 4sts total on the [I]right[/I] needle. Then continue with the directions to p2tog 3 times etc.

Buuut, there’s a problem with the math on some of the sizes. Which size are you making?

They’re assuming you’re right-handed and I’ll assume you’re making the smallest size.
If I’m reading that right, you’d start the row with 33 stitches. If you cast off four, which should leave a loop on your right needle, then work three more in whatever pattern you have going, you’ll have four stitches on your right needle and you’ll be ready to work the rest of the row as written. I counted it a couple of times and got the total they have for the end of the row, but knowing my ability to miscount things, keep an eye on it

I have no idea why they used “when there are four stitches on your right needle” as an instruction–I’ve never seen it written that way before.

I think that the reason that they tell you work until there are 4 sts on the right needle is to account for that last stitch that is left on the RH needle after the bind off. They could have said work 3 more sts but this is a way of making sure you count that pesky leftover stitch (although confusing in its own right). I invariably have to count the sts in the directions to see whether that st has been accounted for.

I get the row starting with 29sts (45-12 and then -4 at the beginning of the right side row).
On the wrong side row there’s a balancing -4 for the other shoulder and then the p2tog x3 etc.

Thank you so much for your replies! They don’t make things easy for us novices!! It makes more sense now it’s been explained to me!

I’m actually left handed but knit right handed (I do most things right handed because everything is geared for right handed people!)!

Thank again x