He made fifty loops on the one curtain and fifty loops on the edge of the curtain in the second set, so that the loops lined up with each other.
Make fifty loops on the one curtain and make fifty loops on the edge of the curtain in the second set, so that the loops line up together.
Make fifty loops on the edge of one curtain, the outermost in the first set, and make fifty loops on the edge of the corresponding curtain of the second set.
Make loops of blue yarn on the edge of the last curtain in the first set, and do the same on the edge of the outermost curtain in the second set.
He made loops of blue yarn on the edge of the last curtain in the first set and did the same on the edge of the outermost curtain in the second set.