I am making my second sweater. The first one was a top down and I did great, no problems. I measured the sleeve lenght under the arm and of course tried it on along the way for proper fit. Now I am making a child's sweater. It is a cardigan. The sleeves are made by picking up the armhole stitches and knitting the sleeve in the round. I am decreasing every fifth row and all is well but I am not sure from where I should be measuring the sleeve length. Is it under the arm or from the shoulder? I am to knit eight inches then do the cuff.