Clarification on pattern instructions

I am knitting a garter stitch sweater. The instructions say to leave rem sts on a st holder. Does that mean to move the stitches to a different needle or leave them on them on the existing needle and cast on the new stitches on the same needle with the remaining sts

Here are the instructions…

after ending last row on shape yoke - ***[B] Sleeve: 1st row:[/B] (WS) K20. Leave rem 23 sts on a st holder. Cast on 26 sts for sleeve. 46 sts in total.
[B]Next row:[/B] K31. [B]Turn[/B]. Leave rem 15 sts unworked.

Thanks so much for your help!

For the first set of sts (Leave rem 23 sts on a st holder), it’s probably easier to place them on a st holder, which could be as simple as threading them onto a piece of scrap yarn. It’ll keep them out of the way and keep them from being confused with any other sts.
For the second set of sts (Leave rem 15 sts unworked), they can remain on the needle. You’ll probably be working with them soon anyway.

So, pattern said
*** Sleeve: 1st row: (WS) K20.
I did that
then it says
Leave rem 23 sts on a st holder. I put them on
Now it says
Cast on 26 sts for sleeve. 46 sts in total.

Here is where I am lost. I have 23 sts on a holder on the left of my work. I have 20 stitches knit on my right.

How do I cast on the 20 stitches on that right hook to have the 46 stitches total?

I have a whole new respect for knitters! I learned how to crochet from a book 15 years ago… never had this many ‘huh?’ moments and have made some neat stuff! Now I remember why I have had so many failed attempts with knitting. Not giving up this time thought since I have sites like this with all you amazing and talented people to help!

Move the right needle to your left hand and use the knit or cable CO, then move it back to the right hand and continue with the next instruction. The new stitches probably won’t get knit until the next row.