shape neck and armhole
 

I am a beginner and do not understand the instructions:

Dec1 st at each end of next row, then every foll 4th row 10 times more, every 6th row 4 times, AT THE SAME TIME

My question: what am I supposed to do 10 times more on every following 4th row and 4 times more on every 6th row?

This is from "Mom's striped cardi, page 70, knitsimple magazine, fall 2011

What you are doing all those times is the decrease at each end of those rows. You must be doing the back, or it could be the front of a pullover. At the same time you keep working the decreases for the underarms you will also work some shaping for the neck when you get up to the point it starts.

You should decrease one st at each end of the row.
You decrease at each end of the next row, decrease at each end of the following 4th row 10 times more and decrease at each end of every 6th row 4 times.
The directions "at the same time" refer to whatever instructions come next in the pattern, probably something to do at some other place in the project.