Oh dear, it appears there is an error in the Carrot Cardigan instructions that is baffling some knitters. I will set it straight.
Gauge 24 sts and 33 rows = 4” in St st on smaller needle (note: this is an adjustment, it is printed incorrectly as on larger needles) Tools • Size 6 (4 mm): 32” or longer circular (cir) needle • Size 8 (5 mm): 32” or longer cir needle
The size 6 needle is used for the entire sweater except for the last few inches of the collar. This is knit on a bigger needle to help it fold over nicely.
Hope this clears it up for most people, spread the word!