Slice raw sweet potatoes about 1/4 inch thick. Divide each biscuit into 2 parts. Roll thin, wrap around two slices of potatoes. Melt margarine in baking dish, place wrapped potatoes in dish. (I place them in and turn them over to get both sides covered.) Bring sugar, water, cinnamon and salt to a boil. Pour over potatoes. Bake at 350ºF. for 45 minutes.