I am knitting a hat for my son and after knitting 2x2 rib for 3 inches the next row says to purl to end, inc 2 sts evenly across row. i don't understand what inc 2 sts evenly across row means.
As you purl that first row increase (by whatever method you like, I often use a simple backward loop added over the right hand needle for this type of situation) two stitches so that they are not right next to each other but about the same distance from each other when the hat is sewn together. I'd purl across about 1/4 of the stitches, add a stitch and then purl to where you have 1/4 left to work and add another. It doesn't have to be exact. Eyeballing it is good enough.
What the phrase means is to increase 2 stitches evenly distributed across the piece of work.