Suzeeq, thankyou, it means to do seven square '1's' using A
The full pattern for square A reads
cast on 16sts loosely
1st row knit
2nd row purl
these 2 rows will now be referred to as st-st
working in st-st (throughout) work 24 rows more.
Cast off loosely
Using A, work 7 of square 1
Using B work 8 of Square 1
Using C work 10 of square 1
Using D work 6 of square 1
Yes, on the pattern there is a diagram of how to put the squares together in the correct order. I hadn't read the full pattern correctly as there are only instructions for 4 squares, but the jacket is made up of 60 squares altogether. If I'd read more closely I would have seen I didn't have instructions for 60 squares!
Thankfully too, the lady where I got the pattern and wool is going to put me in touch with someone who can sew it all together when I finish otherwise I wouldn't have touched it with a 10ft pole!