I’ve been knitting socks for me - I’ve been doing the provencial (spelling??) cast on and doing the toe up. For me… I wear a size 6 shoe and I’ve been using 64 stitches to do my sock. I’m wondering how many stitches to do for a 5 year old who wears a size 12 kids shoe??
http://www.yarnstandards.com/footsize.html
see if this helps.
Or try finding children sock patterns just to see how many stitches they use to get to the size you need.
A child’s size 12 is 7.33 inches in foot length. The issue for the leg and width, though, is gauge. If you’re getting 8 sts = 1", then I would find a child’s pattern that was also that gauge. Try www.knittingpatterncentral.com for free patterns.
Oh, and it’s “provisional” cast on. It means temporary or not fully worked out. Provincial means local, unsophisticated, rustic. Well, come to think of it, that could apply to that cast on, too!