Casting on--how to figure out how many sts

I am relatively new to knitting. I have yarn that is 10sts and 16 rows=4" with #11 needles. I want to make a 4" wide scarf. The directions say CO a mulitple of 12 + 6 sts. What does that mean? I thought I would divide 10 by 4 = 2.5. Then 2.5 x 4" (scarf width) = 10 sts to cast on. But 10 is not a multiple of 12…help! Thanks, Lisa

Sounds like whatever pattern you’ll be knitting into your scarf requires a multiple of 12, and the extra 6 are probably for 3 stitches on each edge. If your yarn is 10 st = 4", then I’d probably just cast on 18 (12 + 6). Sounds like that should be about a 7 1/2" scarf. If you want a 4" scarf, you’re going to have to go to a much finer yarn.

swatch! cast on 20 stitches and see what you get!

and if you want a 4 inch wide scarf, and a pattern that is 12 +6, (a minimum of 18 stitches to have a pattern) you either want a 8 inch scarf, a different yarn/gauge, or a different pattern!

you can’t knit a 12(+6) stitch pattern into 4 inch scarf if you get a gauge of 10 stitches =4 inches!

this is the designer cunnundrum! finding the right pattern, at the right gauge for the right yarn!