Pattern Gauge Help
So I'm starting a new, and more difficult, hat. This one's for my son. It's from 60 Quick Knits using Cascade 220 (which I'm finding I just ADORE, by the way).
For anyone who has or is familiar with the book, it's pattern 9, the monkey hat I'm working with (and yes, I realize there is an error at the start of the pattern. My lys included a corrections insert).
The Guage is written as follows:
20 sts and 42 rnds to 4"/10cm over garter st using size 7 (4.5 mm) needle
I haven't swatched for a round project before. The last hats I made were able to be knit straight and the gauge swatch was flat. For this new hat, do I need to knit on dpns in the round for gauge or on my circular needles? The pattern calls for both to be used at different points, so which one do I use to assess the gauge?
If dpns, the pattern called for five, so I would use all five for the gauge, correct?