New on the forum and need help

#1

I recently got 400 Knitting Stitches: A Complete Dictionary of Essential Stitch Patterns. I want to knit a sweater for my dog using the “Cobblestones” pattern on page 21, but I’m having trouble figuring out how many stitches to cast on because the beginning of the pattern confuses me. The pattern itself looks like a bunch of offset circles.
The pattern says: "For symmetry, work on a multiple of 18+5 sts, + 1 edge st on each side."
I’m most confused about this!! And why not just say 23 stitches instead of 18+5? I’m sure there’s an obvious reason, but the intro to the book doesn’t say how the pattern works.
Can anyone help??!
Here’s the rest of the pattern, just in case: (I do understand how to read this pattern and the chart, I just don’t know how many sts to cast on.) “1st (right side of work), 3rd, 11th, 15th, 15th, and 23rd rows: Knit all sts.
2nd and every alternate row: Work each st in the manner that it presents.
5th, 7th, and 9th rows: K1 (edge), K9, P5, K4; repeat from * to * to last 6 sts, K5, then K1 (edge).
17th, 19th, 21st rows: K1 (edge), P5, K13; repeat from * to * to last 6 sts, P5, then K1 (edge). These last 24 rows form pattern.”

I did a swatch by casting on 24 stitches (18+5+1edge) and it doesn’t look like the picture. It doesn’t make any sense. Can someone help me because there are so many new stitches that I want to learn and now I am completely lost.

Thanks!!!

#2

"For symmetry, work on a multiple of 18+5 sts, + 1 edge st on each side."
I’m most confused about this!! Why not just say 23 stitches instead of 18+5?

Because the pattern itself is 18 stitches. The other 7stitches (+5, 1 on each side(2)) are window dressing.
You need to figure out how wide you need your object to be (say 40inches). Then you need to know how wide the 18stitches will be when knit (say 10inches). Then you divide desired length by pattern length (40/10) to determine how many sets of 18stitches to CO (4).
(18x4)+5+2=79 stitches need to be CO.

#3

I think the key is in this set up row:
5th, 7th, and 9th rows: K1 (edge), K9, P5, K4; repeat from * to * to last 6 sts, K5, then K1 (edge).
If you only did one repeat of the pattern you would have the edge st (1), the repeat of k9, p5, k4 (18sts) and then the last 6 sts, k5 (5sts plus the second edge st). So the basic repeat is 18 sts, you finish with 5 sts and on eadh end ther is an edge st. That makes the 18st repeat + 5 + 2 edge sts.

#4

The pattern itself is only 18 sts repeated, the plus 5 may be for a partial repeat, and/or edge sts, then you need more sts for an edge. BUt presuming you’re going to knit the pattern across more than 23 sts you’d take 18 times 2, or 3, or 5, then add the 5 sts, and any edge sts you may want if they’re not already in the basic pattern. If you were going to knit a washcloth say, you’d want 18 times 2, 36 + 5 for 41, then 2 more for the edging for a total of 43.