EDITED to add : I made one pair of fingerless gloves that came up just to the wrist, and then decided to make a longer pair. .. and as the pattern is the same (almost), I'm going to edit in the difference(s)
IF there is no decrease, and you find that Round 4 measurements will work perfectly up the arm, then continue rep of Round 4 till you have the length you need for your glove.
Increase arm length ideas : So as I mentioned before, I'd made the multi colored pair before, and then decided to make a longer pair. I've just added colors in this second pair to make it stand out - so you can do it in all one color or variegated yarn as well.
For the longer arm length, you just continue with the simple arm pattern all the way past the wrist up the arm, till you have the length needed. You need to keep checking that it fits snugly around the arm, as the arm tends to change in circumference as it advances towards the elbows. End with a neat row of picot for a good finish.