I am knitting the arms of a sweater. I am using double pointed needles where there is a marker at the underarm part of the sleeve. This marker is the beginning of the round. I have to decrease (ssk- I’m assuming this is when I start a new round after I have passed the marker) and then when I get to the marker at the end of the row I have to knit two together. Does this make sense? Also, when you are decreasing knitting a sleeve like this are the decreases done on the underneath side of the sleeve? I guess I just need to understand where the decreases will occur.