Trouble understanding instructions

The pattern for the jumper that i am just starting (or at least attempting to) says
"with 4mm needles cast on 64[68: 72: 76:] sts., and work in K1 P1, rib for 8cm
I have CO the stitches but what i am stuck with is when it says do the rib patten for 8cm… does it mean 8cm on that row or do multiple rows until all the rows add up to 8cm?

Oh and i am new here so hello everyone :slight_smile:

Hi there, and welcome!

It means 8cm in length from your cast on edge, so do as many rows as it takes to get the length.