Modifying sleeves on baby cardigan

Ok… so the pattern calls for knitting the sleeves seperately (flat) seaming them and then sewing them on to the cardigan. I’d really rather not have to seam or sew any more than the shoulders that I already did.

I’m thinking I could just pick up the 36 stitches at the shoulder and knit down the sleeve in the round. My only concern is when to start the decreases since the pattern doesn’t say knit x amount of rows. Instead it wants the finished sleeve to measure 5.5 inches.

Here’s the sleeve portion of the pattern

SLEEVES
With A, cast on 28 (28, 30, 30) sts.
Knit 4 rows.
Change to St st and work 8 (10, 12, 16) more rows with A,
11 (13, 16, 20) rows with B, then continue with C, AT THE
SAME TIME, inc 1 st at each edge every 4th row 4 (6, 9,
11) times – 36 (40, 48, 52) sts. Work even until piece
measures 5 1/2 (6 1/2, 8, 10) in. (14 (16.5, 20.5, 25.5)
cm) from beg. Bind off.

GAUGE:
17 sts + 24 rows = 4 in. (10 cm) in St st (k on RS, p on WS).

Is there any way to know when to start the decreases so the sleeve length comes out correctly? I was assuming that if 24 rows = 4 inches, shouldn’t 6 rows be about an inch? … I’m honestly not sure how that works… sigh (I’m knitting the smallest size btw)

Hmmm… well… I tried to do math (scary… ) and I ‘think’ if I knit 9 rows before I do the decreases my sleeves will be very close to 5.5 inches. So… I guess I’ll try that and see what happens!!

Bah… ignore my math… I realized it was waaaaay wrong after thinking a little harder about it. I knew I shouldn’t try to do math!

Plus I forgot that gauge for stockinette can be different while knitting in the round… sooooo… just gonna start knitting and hope for the best! It’s just a baby’s sleeve right… shouldn’t matter too much… ;o)