i have a pattern for a baby hat that calls for 84 stitches to be cast on, with a guage of 5 stitches per inch on size 6 needles. i want to knit it on size 2 needles with a smaller yarn that knits up at 9 stitches per inch on my 2s. (i've already knit something else with this yarn on my 2s, and i loved the feel of the knit afterwards, that's why i want the hat the same)
here's my question: if 84 stitches divided by 5 per inch equals 16.8 inches in the original pattern, can i multiply my 9 per inch by 16.8 inches to get the new cast on number of 151? the decrease is very simple, i could definitely figure it out for a different cast on number, so i'm not worried about that, i'm just wanting to know if people think this is the right way to go about it in general.