Sprinkle strawberries with 1 cup of sugar, let stand 1 hour. Heat oven to 450ºF.  Mix flour, 2 tablespoons of sugar, the baking powder and salt in a medium bowl. Stir in milk and margarine just until blended. Sprinkle a surface lightly with flour. Turn the dough onto the surface. Gently smooth into a ball, knead 20 to 25 times. Roll or pat dough 3/4 inch thick, cut into shortcakes with a floured 3 to 3 1/2 inch biscuit cutter. Place on an un-greased cookie sheet. Bake until golden brown, 10 to 12 minutes. Split warm shortcakes crosswise, fill and top with strawberries. Serve with whipped cream. Serves 4. (Sweetened whipped cream): Beat 1 cup of chilled whipping cream and 2 tablespoons of powdered sugar in a chilled bowl until stiff.